Martial arts background Sergei started being interested in sports when he was still in
kindergarten, being taught at first by his father. Kharitonov started training boxing seriously when he was ten or eleven years old, following an incident when a drunken adult passer-by broke up a scuffle between Sergei and another boy by lifting Sergei in the air, hitting him in the face and cutting his eyebrow with that punch. The man justified his behavior by saying that Sergei should not have been hitting a grounded opponent. At the age of sixteen, Kharitonov started studying
Combat Sambo. During his studies in the Airborne Troops Academy, Sergei started competing in hand-to-hand combat (simplified form of Combat Sambo) and MMA. After Kharitonov graduated from the Academy, he was contacted by Vladimir Pogodin, the manager of the Russian Top Team, who invited him to join the club. At first, Sergei was invited to be
Fedor Emelianenko's
sparring partner, who taught him many
ground fighting techniques, including
striking on the ground and
submissions. Sergei kept competing at various Russian MMA competitions, and in October 2003 he debuted in Pride Fighting Championships, one of the top two leading MMA organizations in the world at that time. Sergei trains with the Russian national boxing and Sambo teams, as well as some freestyle wrestlers. He also recently added
Muay Thai training to his regimen, and, according to him, he even borrows some elements from
karate.
K-1 Hero's On September 17, 2007, Kharitonov TKO's Alistair Overeem in the first round in the ''Hero's 10: Middleweight Tournament Final'' event, avenging a previous loss.
DREAM Kharitonov's next fight was scheduled to be against
Mighty Mo at
DREAM 6 on September 23, 2008. However Mighty Mo was forced to withdraw due to a back injury. Jimmy Ambriz was Mighty Mo's replacement. Sergei scored a win in the first round by submission via strikes. At Dream 8
Jeff Monson secured Sergei in a
North/South Choke. The Russian tried punching his way out but was soon forced to tap for the first time in his career.
Strikeforce Sergei signed a deal to fight for
Strikeforce and made his debut on February 12, 2011. He faced former UFC Heavyweight champion
Andrei Arlovski in the opening round of Strikeforce 2011 Heavyweight Grand-Prix. Sergei defeated Andrei Arlovski by knockout in the first round. Sergei faced
Josh Barnett, who defeated
Brett Rogers on June 18, 2011, at
Strikeforce: Dallas, in the next round. He lost via submission in the first round.
Post-Strikeforce On June 1, 2012, he submitted John Delgado by keylock at the MMA: Russian Open Championship in St.Petersburg, Russia. Kharitonov has signed with M-1 Global and Oleg Taktarov's Fight Star MMA Promotion and was expected to fight
Travis Wiuff in December 2013. This fight did not materialize, but on November 15 of that year Kharitonov faced Alexey Kudin at M-1 Challenge in Surgut, Russia and defeated him by TKO (punches) in the second round. In his next appearance, Sergei defeated Tyler East via second-round TKO at Tech-Krep Fighting Championship - Prime on March 21, 2014. Kharitonov was expected to face
Satoshi Ishii on November 11, 2014, at M-1 Challenge 53: Battle in the Celestial Empire. However, Ishii withdrew from the bout due to injury. He instead faced Kenny Garner at the event, which took place on November 25, with Kharitonov winning via doctor stoppage in the third round.
M-1 Global Kharitonov faced
Alexei Kudin on November 15, 2013, at M-1 Challenge 43. He won the fight via TKO in the second round. Kharitonov beat Kenny Garner at M-1 Challenge 53 on November 25, 2014, via TKO (doctor stoppage) in 3 round. In the rematch he wins over Kenny Garner again on July 3, 2015, at M-1 Challenge 59 via TKO in the first round.
Bellator MMA On February 3, 2016, it was announced that Kharitonov had signed with Bellator. Kharitonov made his debut against
Javy Ayala on November 4, 2016, at
Bellator 163. He lost the fight via knockout in the first round. Kharitonov faced
Chase Gormley at
Bellator 175 on March 31, 2017. He won the fight via knockout in the first round. Kharitonov faced
Roy Nelson in the
Bellator 207 co-main event on October 12, 2018. He won the fight via knockout in round one. After the Nelson fight, Kharitonov signed a new multi-fight contract with Bellator and headlined
Bellator 215 against
Matt Mitrione on February 15, 2019. Unfortunately, the bout ended in a No Contest just 15 seconds into the first round after Mitrione landed an accidental groin strike and Kharitonov was unable to continue. Kharitonov faced Mitrione in an immediate rematch six months later at
Bellator 225 on August 24, 2019. He won the fight via TKO in the second round. Kharitonov headlined
Bellator 234 against
Linton Vassell on November 14, 2019. He lost the fight via TKO in the second round. Kharitonov faced Fernando Rodrigues Jr. at World Total Kombat Federation 5 on February 23, 2020. He claimed the WTKF Heavyweight Championship via second-round knockout. Kharitonov faced
Cheick Kongo on August 20, 2021, at
Bellator 265. He lost the fight via a rear-naked choke in round two.
Parus FC Kharitonov defended his Parus FC Heavyweight Championship against
Fábio Maldonado at an Parus FC event on November 6, 2021. He won the bout via TKO in the first round.
Eagle FC Kharitonov, as a replacement for
Antônio Silva, faced
Tyrone Spong on January 28, 2022, at
EFC 44. He won the fight by technical knockout in the second round.
MMA Series Kharitonov returned after a year and half break from MMA to face Tiago Cardoso on September 23, 2023 at MMA Series 72, winning the bout via TKO stoppage in the first round. ==Kickboxing==