She began playing tennis at the age of five. In 2001, 12-year-old Karatantcheva won the Orange Bowl tournament for her age group, defeating
Alisa Kleybanova in the final. Early in her playing days, she trained for approximately six months at the famous
IMG Academy of
Nick Bollettieri. Sharapova then defeated Karatantcheva in three sets in the third round. On April 19, she played her first match for the
Bulgaria Fed Cup team. Because of her age, Karatantcheva was restricted in the number of tournaments she was able to play. In August, she reached the quarterfinals of a WTA tournament in Vancouver, British Columbia, and qualified for the
US Open, before losing to eventual champion
Svetlana Kuznetsova in the first round. Karatantcheva also reached the quarterfinals of the WTA tournament in Québec City, and captured another ITF tournament in December at Palm Beach Gardens. In 2004 she became the French Open junior champion without losing a set, defeating
Romanian
Mădălina Gojnea in the final.
2005: Breakthrough and first French Open quarterfinal The 2005 season was Karatantcheva's breakthrough season. She started off the year at the tournament in Gold Coast, Australia by qualifying, and then defeating the tournament's No. 7 seed
Elena Likhovtseva before falling in the quarterfinals. At 15 years and 5 months, she qualified for the
2005 Australian Open, losing to the No. 4 seed
Maria Sharapova in the first round. At
Wimbledon, she lost to Sharapova once again, being able to win just one game. In 2005, Karatantcheva also won a European club championship in Rennes as a member of the Cherno More Elite team (Bulgarian: Черно море Елит). Her teammates were Virginiya Trifonova,
Maria Penkova and
Tsvetana Pironkova. She was also honoured by the Bulgarian Tennis Federation as the "Best female tennis player of the year". On December 20, 2005, the French sports newspaper ''
L'Équipe'' reported that Karatantcheva had failed a drug test earlier in the year at Roland Garros (after the 1/4 final match against Likhovtseva), and that she had appeared in front of a three-person panel of judges to explain the results. The newspaper claims that Karatantcheva said she was pregnant at the time of the test, which would explain the high levels of
nandrolone in her system. Karatantcheva has denied all allegations, saying "I am shocked. I have not appeared before judges of the international federation."
2006–2007: Doping scandal and two-year suspension On 11 January 2006, the ITF issued a two-year ban after two positive drug tests for nandrolone. While Karatantcheva has claimed she was pregnant at the time of one of the tests, another laboratory carried out a pregnancy test on her urine sample, and it tested negative. On 3 July 2006, the
Court of Arbitration for Sport denied her appeal to overturn the ban with the argument that said nandrolone was found in concentrations which were inconsistent with the normal levels for that stage of pregnancy. Karatantcheva did not play any matches in 2006 or 2007 following her drug ban. She mainly trained in
Pravets.
2008: Back to the WTA Tour Karatantcheva's first match after the ban was in a pre-qualification tournament for a wildcard into the $25k tournament in Surprise, Arizona. She won three matches in one day to win the event and thus won a wildcard for the qualifying draw, in which she beat Susanna Lingman, Maria Kondratieva, and
Kristína Kučová. In the main draw, Karatantcheva beat the fifth seed
Sunitha Rao in three sets in the first round, and
Robin Stephenson in the second round. In the quarterfinals, Karatantcheva beat
Magdaléna Rybáriková in two sets, and in the semifinals she defeated the second seed
Viktoriya Kutuzova. In the finals, Sesil played a tough three-set match and overcame the eighth seed American
Angela Haynes. In late January, still unranked, she entered another $25k tournament at La Quinta, and again battled through three rounds of qualifying into the main draw, despite a scare in her qualifying match against American player
Stacia Fonseca, who took the first set. Having fended off a spirited challenge from second-seeded
Angelika Bachmann in the first round of the main draw, she made light work of subsequent opponents en route to the semifinals, where for the second tournament in succession she was scheduled to play Viktoriya Kutuzova. This time, the match ran to three sets, but Karatantcheva ultimately prevailed in three sets. In the final, Karatantcheva defeated the third seed
Sandra Klösel. Karatantcheva attracted criticism from the Bulgarian tennis federation for competing at La Quinta in preference to participating in Bulgaria's
Federation Cup tie scheduled the same week. She was accused of breach of contract and threatened with a fine, but the Bulgarian teenager stood by her decision, which she had taken on the grounds that it was proving extremely difficult for her to gain entry even to low-level tournaments following the loss of all her ranking points and any right to protected ranking status after her ban, so she needed to work at re-establishing herself at least in the mid-hundreds of the
WTA rankings as a matter of priority before tending to national team commitments. In February, the Bulgarian was awarded a wildcard into the $75k Midland Classic, but her winning streak came to an abrupt end as she was defeated in the first round by qualifier
Valérie Tétreault of Canada, who had raced through the three qualifying rounds for the loss of just nine games, five of them against former top 50 star
Mirjana Lučić. Karatantcheva then attempted to qualify for the WTA Tier III event in Memphis but lost in the first round of qualifying to
Hana Šromová of the Czech Republic. In early March, she qualified for the $50k Las Vegas event including victories over
Amber Liu and
Elena Bovina. However, she lost in the first round of the main draw to wildcarded American
Madison Brengle. She also received a wildcard into the qualifying event for the Tier I event at Indian Wells but lost in the first round of qualifying to
Evgeniya Rodina. Her luck changed however, when, at the end of March, she managed to qualify and reach the final of the $50k event in Latina, losing to
Iveta Benešová in straight sets. In April, she reached the quarterfinals of the $25k event at Civitavecchia, losing to
Betina Jozami of Argentina in straight sets. Her route through to the final of the $25k event in Palm Beach Gardens, Florida, included a victory over seventh-seeded
Lauren Albanese. Argentinian
Soledad Esperón beat her in two sets in the final. In May, she played her first WTA main-draw match since her suspension in Fes, Morocco against
Elena Baltacha which she won in straight sets. In June, Sesil reached the quarterfinals of the $75k tournament in Marseille. In the qualifications of Wimbledon, she lost in the second round to
Magdaléna Rybáriková from Slovakia.
2009: Representing Kazakhstan On 10 January 2009, it was announced that Karatantcheva would take Kazakh citizenship and compete for the
Kazakhstan Fed Cup team. She did not participate in Fed Cup competitions for Kazakhstan during 2009. In tournament play in January, she reached the second round (as a qualifier) at the Brisbane International, defeating top 50 player Iveta Benešová along the way and then backed it up by playing (and winning) her first main-draw major match (again as a qualifier) at the Australian Open. She then lost in the second round to
Peng Shuai. This was to be her last main tournament playing for Bulgaria until 2015.
2010: First WTA Tour semifinal At the
Pattaya Open, Karatantcheva reached her first WTA semifinal, before losing to
Tamarine Tanasugarn. Karatantcheva qualified for the
Birmingham Classic where she reached the quarterfinals winning five matches in a row, upsetting
Yaroslava Shvedova in straight sets in the second round, before losing to second seed Maria Sharapova.
2011 Karatantcheva failed to qualify in
Brisbane,
Melbourne,
Pattaya, and
Monterrey. She reached the final of a $25k event in Clearwater, Florida, losing to
Ajla Tomljanović. At the
French Open, she lost to
Olga Govortsova in the final round of qualifying. After barely missing out on qualifying for the
Birmingham Classic, Karatantcheva fell to
Arina Rodionova in the first round of qualifying of
Wimbledon. She took a two-week break following Wimbledon. She returned at the
Palermo Ladies Open, where she qualified for the main draw. She drew second seed
Roberta Vinci in the first round. Although Karatantcheva played well she was beaten in straight sets. She then competed in two $100k events – in
Bucharest and
Astana, losing in the early round of both tournaments. She then failed to qualify for the
US Open, marking the first year since 2009 that she had not competed in the main draw of a major. Her poor form continued, losing in the first or second rounds of four more ITF tournaments. She began to improve her game by advancing to the semifinals of a $50k event in Troy, Alabama. She then competed in a $25k tournament in
Rock Hill, losing in the quarterfinals. Karatantcheva then played at the $50k event in
Grapevine, Texas, where she advanced to the final, losing to eighth seed
Kurumi Nara in three sets. Following her performance in Grapevine, Sesil achieved her best result of the year by winning a $75k tournament, the
Goldwater Women's Tennis Classic, in Phoenix, Arizona, the biggest title of her career. She won the title dropping only two sets the entire tournament, defeating a seeded player along the way. Karatantcheva's recent change in form has propelled her well back inside the top 200 and she established herself as one of the leading Kazakh players.
2012 Karatantcheva began the year ranked World No. 139. She failed to qualify in Brisbane and at the Australian Open. She then competed in the $100k tournament in
Cali. Unseeded, she advanced to the semifinals before losing to
Mandy Minella. She then played at the
Copa Sony Ericsson Colsanitas and
Monterrey Open. Although she qualified for both, she lost in the first round to
Catalina Castaño and Yaroslava Shvedova, respectively. Sesil then qualified for the
Abierto Mexicano Telcel. Although she put up a fight, Sesil was defeated by sixth seed
Johanna Larsson in three sets, in the first round. Karatantcheva committed 18 double faults during the match – almost an all-time high in WTA history. Karatantcheva then competed at the
Indian Wells Open and the
Miami Open, losing in the first round of qualifying for both tournaments. Despite the losses, she rebounded and reached the final of a $50k event, losing to
Arantxa Rus. Karatantcheva headed to Portugal for the
Estoril Open. In the first round of qualifications, she drew Italian
Maria Elena Camerin, whom she defeated in three tough sets. In the second round of qualifying, however, she was defeated by
Mariana Duque-Marino, despite the fact she was leading with a break in the deciding set. Karatantcheva then lost in the first round of qualifying of the
Madrid Open. At the French Open, she lost in the final round of qualifying to
Alexa Glatch. However, she was offered a spot in the main draw after the withdrawal of
Vera Zvonareva. She played
Tímea Babos in the first round and won in two easy sets. This was Karatantcheva's first Grand Slam tournament main-draw appearance in almost years. In the second round Karatantcheva took the first set against
Carla Suárez Navarro, but subsequently lost the next two and was eliminated from the tournament. She opened her grass-court season at
Birmingham where she entered the qualifying draw and defeated local girl Francesca Stephenson but fell to Thailand's
Noppawan Lertcheewakarn in the final round. However, she was offered a place in the main draw as a lucky loser due to the withdrawal of another player. She faced another Thai player, Tamarine Tanasugarn, defeating her in straight sets. Her run was ended in the second round by eighth seed Ekaterina Makarova. She then lost in the final round of qualifying at
Wimbledon. Despite the loss, her ranking climbed due to her improved result from 2011. Karatantcheva then played at the
Stanford Classic. She fell in the first round of qualifying. She then qualified for the Premier-level
Carlsbad Open. She was points away from winning, but was finally beaten by
Melinda Czink in the first round. She then competed at the second annual Washington Open where she lost to
Sloane Stephens in the first round. She then continued her hardcourt season at the
Rogers Cup in Montreal. As the 18th seed in qualifying, she won three matches for a place in the main draw. In the first round she dismantled
Sorana Cîrstea, without losing a single game, in only 43 minutes. Karatantcheva lost to 16th seed
Lucie Šafářová in the second round in straight sets. Her ranking climbed to No. 92, her highest ranking since 2005. Karatantcheva then played at the
Western & Southern Open, qualifying into the main draw by beating world No. 64
Arantxa Rus and
Olga Govortsova. In the first round of the main draw, she won against fellow qualifier
Kiki Bertens, but was soundly beaten by former world No. 1, Caroline Wozniacki, in the second round. Her next tournament was the
US Open. Ranked world No. 85, she was given direct entrance into the main draw. She lost to
Lourdes Domínguez Lino in the first round. Following the US Open, Karatantcheva competed in
Québec and
Seoul, losing in the first round of both tournaments. She continued by then losing in the qualifying draw of the next four events in
Tokyo,
Beijing,
Linz, and
Moscow. Her final tournament of the year was in
Phoenix, where she was the defending champion and second seed. She suffered a shock straight set loss to world No. 217
Shelby Rogers in the first round. Despite the loss, she ended the year at No. 93, her first year-end ranking inside the top 100 since 2005.
2013 Karatantcheva began the season at the
Australian Open, losing to 6th seed
Li Na in the first round. She next played for Kazakhstan in
Fed Cup. Placed in the Asia/Oceania Zone Group I in
Astana, Karatantcheva played with
Galina Voskoboeva to beat
Rutuja Bhosale and
Ankita Raina, securing Kazakhstan's 3–0 sweep over
India. Following Kazakhstan's win over
Thailand, they defeated
Uzbekistan in the Group I promotional play-off. Their win over Uzbekistan has catapulted Kazakhstan into the World Group II play-offs in April for the first time ever. Karatantcheva then played at the WTA 125,000 event in
Cali, losing in the quarterfinals to
Catalina Castaño in three sets. She then lost in
Memphis qualifying before losing to
Francesca Schiavone in the second round at
Acapulco. Karatantcheva then qualified for the
Indian Wells Open, but lost to
Lara Arruabarrena in the first round. At the
Miami Open, she entered the qualifying draw and defeated
Anastasia Rodionova in the first round, saving two match points and battling almost three hours before winning. She lost in the final round to
Sílvia Soler Espinosa. Karatantcheva closed the hard court season with a first round loss in
Osprey to
Olga Puchkova. Karatantcheva opened her clay court season by falling in the qualifying rounds in
Charleston and
Oeiras. She then won only two matches in her next four tournaments before heading to
Wimbledon, where she lost in the final round of qualifying to Austrian
Yvonne Meusburger in a close three-set match. Following Wimbledon, Karatantcheva played two more clay-court events in
Budapest and
Båstad, losing to
Simona Halep and Serena Williams, respectively. After skipping the first week of the
US Open Series, Karatantcheva entered the
Southern California Open in Carlsbad. She played the qualifying draw and won three consecutive matches against Chieh-yu Hsu,
Katalin Marosi, and
Ivana Lisjak for a spot in the main draw. There, she drew Julia Görges and defeated the world No. 42 in straight sets. She advanced to the second round but lost to eventual champion
Samantha Stosur, winning only five games. Despite the loss, her win over Görges was the biggest win of her season. Her next tournament was the
Rogers Cup in Toronto where she fell in the first round of qualifying. Her ranking plummeted to No. 163 as a result of her failure to defend 2012's second round points. At the
US Open, Karatantcheva played the qualifying draw and won two matches before losing out to Mirjana Lučić-Baroni in straight sets. Following the US Open, Karatantcheva played at the
Challenge Bell, again entering the qualifying draw. She beat Élisabeth Fournier,
Petra Rampre, and
CoCo Vandeweghe to enter the main draw. She played fellow qualifier
Amra Sadiković and beat the Swiss in straight sets. In the second round, she lost to fifth seeded local hope
Eugenie Bouchard. She returned to the United States to compete in two ITF Circuit events in
Albuquerque and
Las Vegas, losing in the first round of both tournaments. Her final events of the season saw her lose in
Linz qualifying, bow out to
Karin Knapp in the first round of the
Luxembourg Open, and lose in the first round of an ITF event in Nantes.
2014 Karatantcheva made her 2014 debut at the
Hobart International, losing in the first round of qualifying to Belgian
Alison Van Uytvanck. At the
Australian Open, she was seeded 22nd in the qualifying draw and lost there in the first round to
Duan Yingying in straight sets. For Kazakhstan in
2014 Fed Cup in the Group I final position play-off, Karatantcheva played
Liu Fangzhou and defeated the Chinese in three sets, ultimately sending Kazakhstan into third place in the Asia/Oceania Group I Zone. After that, Karatantcheva competed in
Midland, losing out to young American
Victoria Duval, and then traveled to Brazil to compete at the
Rio Open and
Brasil Tennis Cup. In Rio, she fell in the qualifying competition to
Verónica Cepede Royg. In Florianópolis, however, she was more successful with qualifying wins over world No. 95
Anabel Medina Garrigues and
Alexandra Panova, the latter match lasting over three hours. Her run was ended in the first round by
Kiki Bertens. Karatantcheva proceeded to compete in
Osprey, but lost to
Gioia Barbieri in the first round. At the
Family Circle Cup, she played qualifying and overcame Sanaz Marand before bowing out to
Alla Kudryavtseva. She next played at the
Dothan Pro Tennis Classic, but suffered another loss, going down to world No. 125
Michelle Larcher de Brito in the first round. Karatantcheva's final clay-court event in the United States was in Charlottesville, in which she was able to pick up form by reaching the quarterfinals. For the second consecutive year, she entered the
Nürnberger Versicherungscup, but was defeated in the qualifying draw by German
Nina Zander. At the
French Open, she won one match in the qualifying draw but would progress no further, as she was eliminated by
Laura Siegemund in what was a tough three-set match. She would then compete in
Marseille, advancing to the quarterfinals before going down to Johanna Larsson in a final-set tiebreak. Karatantcheva elected to skip all grass court events before Wimbledon, and suffered another Grand Slam defeat, this time at the hands of young Estonian
Anett Kontaveit in the second round of qualifying. She entered the inaugural
Bucharest Open, winning three qualifying matches before losing to Sílvia Soler Espinosa in the first round. Karatantcheva then played qualifying at the
İstanbul Cup but was beaten in the first round by
Ana Konjuh of Croatia. She returned to the ITF Circuit at the $50k
Powiat Poznański Open in Sobota, advancing to the final having only dropped a set, but suffered a disappointing three-set loss there after winning the first set. It was her first final since April 2012. At
US Open qualifying she was beaten in the first round by
Melanie Oudin. Karatantcheva returned to action at the
Canadian Open as a direct entrant in the main draw. She began with a win over
Sanaz Marand in the first round and squared off against third seeded
Kristina Mladenovic in the second, edging the Frenchwoman in a match that lasted over two-and-a-half hours. Karatantcheva subsequently moved on to the quarterfinals but was defeated there by
Mirjana Lučić-Baroni, who would go on to win the tournament. In October, Karatantcheva announced that she had decided to play for her home country Bulgaria again. She and her father first made the decision known to the Bulgarian public in an interview for
TV7. Her switch back to Bulgaria was finalized a few weeks later and she reappeared under the Bulgarian flag in the 20 October WTA rankings.
2015: Representing Bulgaria once again Karatancheva's first tournament of the year was the
Auckland Open, where she lost in the third round of the qualifying competition to
Urszula Radwańska. Karatancheva also failed to qualify for the Australian Open, losing in the second qualifying round to
Alexandra Panova. In February, she participated at the
Abierto Mexicano where she was defeated in straight sets in the third qualifying round by
Lucie Hradecká, but nonetheless reached the main tournament as a
lucky loser. Karatantcheva then eliminated
Marie Bouzková, Kiki Bertens and
Monica Puig to secure herself a place in the semifinals for the second time in her career. She subsequently lost to fifth seed
Timea Bacsinszky in two sets. Next, she played at
Monterrey Open, where she lost in the first round of qualifying. Despite the setback, Karatantcheva was nonetheless able to stay on course towards improving her ranking by qualifying for the main phase of the
Indian Wells Open shortly after that. In the first round, she managed a two-set victory over compatriot and friend
Tsvetana Pironkova. This was the first time since 2000 that two Bulgarian women had met in the main draw of a WTA tournament. Karatantcheva then suffered a defeat in straight sets to CoCo Vandeweghe. Next, Karatantcheva qualified for the main draw of
Miami Open, where she reached the second round, defeating
Lauren Davis, then ranked No. 61, in the first round in straight sets, and losing to 21st seed
Garbiñe Muguruza. Her ranking improved to 109. Next, at the Family Circle Cup in Charleston, she qualified for the main draw, beating
Arantxa Rus and
Louisa Chirico along the way, and lost in the first round to ninth seed Samantha Stosur. At the
French Open, Karatantcheva was seeded 3rd in the qualifying draw and she qualified for the main draw. In the first round she defeated former world No. 1, Jelena Janković, in straight sets, which allowed her to return to the top 100 in the WTA rankings. Then, she lost in the second round to
Irina Falconi in three sets. Due to her improved ranking, Karatantcheva entered the main draw at
Wimbledon. In the first round, she lost to Sílvia Soler Espinosa in a tight three-setter match. At the
US Open, Karatantcheva suffered a 1–6, 2–6 loss to
Belinda Bencic from Switzerland.
2016 The new season began with a disappointment at
Brisbane, where she lost in the first round of the qualifying draw. She played at
Sydney, starting once again from the qualifications, defeating Yaroslava Shvedova (after taking a 4–1 lead in the first set and her opponent retiring) in the first round, but then succumbing in straight sets to Magdaléna Rybáriková. In the
qualifying for the Australian Open, Karatantcheva was seeded fourth. However, she was unable to pass the first hurdle, being defeated 6–2, 6–0 by
Jessica Pegula. Karatantcheva did not manage to reach the main draw of the 2016 French Open, losing to
Maryna Zanevska in three sets after taking the first one in the
second round of qualifying, for which she was not among the seeds. Her downturn in fortunes continued in
Wimbledon, where she suffered elimination in the first round of the qualifying competition at the hands of
Shérazad Reix in a hard-fought match that was decided in three sets. In the
qualifying draw for the US Open, Karatantcheva posted a win in three sets against Rebecca Šramková in the first round, but was then defeated by
Elise Mertens in another three-setter.
2017 Karatantcheva did not get past the first hurdle in the
qualifying for the Australian Open, being on the receiving end of a 6–3, 6–2 defeat by
Anna Blinkova. After not participating in the qualifying competitions for the
French Open and
Wimbledon, in late August 2017 she entered the
one for the US Open, where she convincingly defeated Arantxa Rus in the first round, but then lost in a dramatic three-setter match (that was decided by a tiebreak) against American
Claire Liu. In September 2017, Karatantcheva won the title at the
Red Rock Pro Open in Las Vegas, defeating compatriot
Elitsa Kostova in the final by a score of 6–4, 4–6, 7–5.
2018 Karatantcheva played in the qualifying of the
Australian Open, but had to exit in the first round losing 5–7, 6–3, 5–7 to
Irina Bara. She was also eliminated in the earliest possible stage of the qualifying draw for
the French Open, being on the receiving end of a three-set-loss against
Ons Jabeur. The negative trend continued in her first qualifying match for
Wimbledon, in which she emerged second best to
Mayo Hibi by a score of 6–1, 3–6, 1–6. The qualifying event for the
US Open saw a repeat of her previous performances, as Karatantcheva did not get past the first round, being defeated 6–3, 2–6, 6–4 by Italian
Martina Trevisan.
2019 Karatantcheva entered the
Australian Open qualifying, taking the first set against American
Asia Muhammad, but eventually lost the other two. Her luck didn't change in the qualifying draw for
Wimbledon when she was defeated in straight sets by Romanian
Elena-Gabriela Ruse, at her last tournament for years.
2023: Comeback to the Tour In April, Karatantcheva participated in a $80k tournament in
Zaragoza, losing in the first round. In May, at the
French Open, she defeated
Fernanda Contreras to reach the
second round of qualifying. It was her first qualifying win at a major since she defeated
Arantxa Rus at the 2017 US Open, and her first at Roland Garros since beating
Zhang Kailin in qualifying in 2016. In August, in the
qualifying for the US Open, Karatantcheva was defeated in three sets by her first-round opponent
Arianne Hartono from the Netherlands. ==Personal life==