2014–15 season In June 2014 Zahorski began training with her partner
Jonathan Guerreiro, coached by
Alexander Zhulin.
2017–18 season: Pyeongchang Olympics Zahorski/Guerreiro started their season by winning the silver medal at the
2017 CS Minsk-Arena Ice Star. Competing on the
Grand Prix series, they placed fourth at the
2017 Cup of China and sixth at the
2017 Skate America. In December 2017 they won the bronze medal at the
2018 Russian Championships. A month later they placed 6th at the
2018 European Championships after placing eighth in the short dance and sixth in the free dance. it was announced by the Russian Figure Skating Federation on 23 January 2018 that Ivan Bukin was not invited to the
2018 Winter Olympics. Because of this, Zahorski/Guerreiro were sent instead. Zahorski/Guerreiro placed thirteenth at the
2018 Winter Olympics. Later they placed eighth at the
2018 World Championships with a personal best score of 180.42 points.
2018–19 season Zahorski suffered from a recurrence of a knee injury over the summer that limited the duo's training time leading up to the new season. Zahorski/Guerreiro started their season at the
2018 Skate America. They ranked third in the rhythm dance and fourth in the free dance, placing third overall. The bronze medal was their first
Grand Prix medal. Guerreiro said: "We haven't had this many free dance run-throughs under our belts, so we just kind of prayed and hoped for the best. Overall, it's a good start." In early November Zahorski/Guerreiro competed at their second
Grand Prix event of the season, the
2018 NHK Trophy, where they won the silver medal with a personal best score of 183.05 points. With one Grand Prix silver medal and one bronze medal they qualified for the
2018–19 Grand Prix Final, where they finished fifth. At the
2019 Russian Championships, Zahorski/Guerreiro placed third in the rhythm dance, several points behind the top two teams but more than three points ahead of fourth-place finishers
Sofia Evdokimova /
Egor Bazin. The team had major problems in the free dance, with Guerreiro's boot laces coming undone early on, and Zahorski making errors on both her twizzles and the one-foot step sequence. Consequently, they dropped to seventh place in the free dance and overall, and were not named to the Russian team to the
European Championships.
2019–20 season Zahorski tore the
meniscus in her knee late in the summer, causing the team to lose significant training time. Zahorski/Guerreiro debuted their programs at the Russian test skates, citing their "
Survivor" free dance as having been chosen to differentiate themselves from the prevailing lyrical style of skating. They did not compete a
Challenger event, and made their return to the
Grand Prix at
2019 Skate America, where they placed fifth. They were fifth as well at the
2019 Internationaux de France. Competing at the
2020 Russian Championships, Zahorski/Guerreiro placed third in the rhythm dance. Third in the free dance as well, they returned to the national podium as bronze medalists. Zahorski said "before this competition, we actually got in training. We had a good two and a half weeks of training, so hopefully, going into Europeans, we'll add more and it will be much better." At the
2020 European Championships, they placed fourth in the fifth in the rhythm dance, but dropped to sixth place after the free dance. They had been assigned to compete at the
World Championships in
Montreal, but these were cancelled as a result of the
coronavirus pandemic.
2020–21 season Zahorski contracted a mild case of
COVID-19 in the off-season, but the team nevertheless debuted at the senior test skates. They competed in the third stage of the Cup of Russia series in
Sochi, beating
Khudaiberdieva/
Bazin for gold by 4.02 points. With the
Grand Prix assigned based primarily on geographic location, Zahorski/Guerreiro competed at the
2020 Rostelecom Cup, coming second in the short program. They were second in the free dance as well, taking the silver medal. Two-time defending national champions
Sinitsina/
Katsalapov sat out the
2021 Russian Championships, making Zahorski/Guerreiro the presumptive silver medalists behind
Stepanova/
Bukin. They indeed placed second in both programs, taking another silver medal. While the
2021 European Championships had already been cancelled due to the pandemic, and assignments for the
2021 World Championships other than the national champions were withheld pending later domestic results. Following the national championships, Zahorski/Guerreiro participated in the
2021 Channel One Trophy, a televised team competition held in lieu of the cancelled
European Championships. They were selected for the Red Machine team captained by
Alina Zagitova. They placed second in both their segments of the competition, while their team finished in first overall. They did not participate in the Russian Cup Final. They placed tenth at the World Championships.
2021–22 season The team's preparations for the new season were hindered by Guerreiro contracting COVID-19 over the summer. As a result of this, their new free dance was not ready for debut by the Russian test skates, and they performed their rhythm dance twice. They subsequently withdrew from their first
Grand Prix assignment, the
2021 Skate America. On 14 October, Guerreiro and Zahorski's coach Svetlana Alekseeva told
TASS that Zahorski was in an infectious diseases hospital. Returning to competition for the
2022 Russian Championships, Zahorski/Guerreiro were fourth in the rhythm dance, 4.60 points behind the newcomers
Davis/
Smolkin, a result which attracted audible boos from audience members in
Saint Petersburg. However, they struggled through the free dance, with Zahorski immediately going to the medical room upon leaving the ice, and dropped to eighth position overall. Guerreiro said afterward "we wanted to fight for a spot on the Olympic team and we knew it would be a hard competition. Tiffany skated well in the rhythm dance, but today it was just physically not possible." In the fall of 2022, Guerreiro announced that he and Zahorski would take indefinite time off from competing to allow Zahorski to recover from her longstanding illness. Zahorski/Guerreiro officially announced their retirement on July 17, 2023. == Programs ==