He won the Fencing World Cup series three times (2004–05, 2006–07, 2010–11), with fifteen titles to his name, and earned five gold medals in the Universiade.

[2] Yakimenko's debut senior competition was the team event of the 2002 World Championships in Lisbon, where he won a gold medal together with Sergey Sharikov, Stanislav Pozdnyakov and Aleksey Frosin.

He claimed his first individual medal at the 2003 European Championships in Bourges: his winning streak was interrupted only in the final by his captain, four-time Olympic champion Pozdnyakov.

[citation needed] In the 2003–04 season Yakimenko climbed his first World Cup podium with a gold medal in Bonn, followed a few months later by a second place in the Nancy Grand Prix.

Russia's director of fencing Sergey Kolganov attributed this below-par performance to overtraining and mental exhaustion after a long season.

At the 2007 European Championships in Ghent, he prevailed over Pozdnyakov in the semi-finals, but he was defeated in the final by an unexpected Jorge Pina from Spain and was relegated to the silver medal.

Yakimenko entered the piste on 31–40 and managed 14–4 in his last bout to get his team to the final, where Russia crushed Belarus 45–30, allowing him to claim his 5th European title in a row.

At the 2008 European Championships in Kyiv he disposed of Olympic champion Mihai Covaliu in the semi-final and met in the final Belarus' Buikevich, who had stopped him in the first round of the 2006 Worlds.

[citation needed] In the 2008–09 season Yakimenko began to work with new coach Christian Bauer, brought from China to replace Boris Pisetsky after the Beijing failure.

In early July he took part in the 2009 Summer Universiade in Belgrade, but tore his Achilles tendon during his quarter-final against China's Zhong Man.

At the European Championships in Sheffield, he edged out Nicolas Limbach in the quarter-finals, then largely prevailed over Max Hartung to meet Boladé Apithy in the final.

Widely considered the favourite in the 2012 Summer Olympics, he was defeated by a single hit in the second round by Daryl Homer of the United States.

The team event proved equally disappointing as top seed Russia were eliminated in the semi-finals by Romania, then lost again to Italy and came home with no medal.

[17] Yakimenko considered ending his career after the London fiasco and took a holiday in California to forget fencing and avoid the negative comments at home.

[18] During his stay in the United States he was deeply moved by a blog article from twice-Olympic champion Mariel Zagunis, explaining that she had received a lot of support despite her disappointing 4th place in London.

[20] He was not fully recovered for the European Championships in Zagreb, but he managed to reach the final despite a difficult bout in the quarters against Italy's Diego Occhiuzzi.

[21] In the team event, top seed Russia, further handicapped by Nikolay Kovalev's knee injury, suffered a shock defeat to Ukraine in the quarter-finals and finished 7th.

Yakimenko later explained that the newly formed team was still in its running-in period and identified Andriy Yagodka's long arm as the main cause of their problems.

In the team event Russia prevailed over reigning Olympic champion South Korea, then defeated Romania to take the gold medal.

[citation needed] The beginning of the 2013–14 season was difficult for Yakimenko: having dropped down to the No.17 spot, he no longer benefited from the Top-16 exemption and had to go through the qualifications phase in each World Cup competition.

[22] At the World Championships in Kazan, Yakimenko edged out Korea's Won Woo-young in the quarter-finals, but ceded to the latter teammate's Gu Bon-gil in the semi-finals.

[23] The team event however fell short of expectations: top-seed Russia were overcome in the semi-finals by Germany, who eventually won the gold medal.

[24] Yakimenko began the 2014–15 season with a bronze medal at the Budapest World Cup, after a defeat in the semifinals to Gu Bon-gil.