Reshetnikov began fencing when he was 11 at the suggestion of his mother. His first coaches were Nikolai Suroegin, who also trained World champion Yuliya Gavrilova, and Pavel Kondratenko, who counted Olympic champion Grigory Kiriyenko amongst his pupils.
Reshetnikov graduated from the Novosibirsk State Pedagogical University, then studied public administration at the Novosibirsk State Agrarian University. He declares his hobbies to be alpine skiing and listening to music, his favourite composers being Rachmaninoff and Tchaikovsky.
In the 2005–06 season Reshetnikov joined the junior national team, where he became friends with Nikolay Kovalev. He won with them a team gold medal in the 2006 Junior World championships at Taebaek City. The year after, he joined the senior national team, which earned gold at the European Championships in Ghent. In 2009 he created a surprise at the European Championships in Plovdiv: ranked 61st before the competition, he won only two of his five bouts in pools and had to go through a qualification round. He then defeated Vincent Anstett, Rareș Dumitrescu, Aldo Montano, Dmitry Lapkes, Gianpiero Pastore and finally Julien Pillet to win the gold medal.
In the 2009–10 season Reshetnikov climbed a World Cup podium for the first time with a gold medal in the Istanbul World Cup, followed by a silver medal in the Akropolis Grand Prix. At the European Championships in Leizpig he was eliminated in the quarter-finals by Germany's Nicolas Limbach, who eventually won the silver medal. He fell against Limbach again in the semi-finals of the World Championships in Paris and came away with a bronze medal. In the team event, Russia defeated South Korea, then Romania and met Italy in the final. Russia came back from an early 10–1 Italian lead to prevail 45–41 and take Russia's first World title since 2005. These results allowed Reshetnikov to enter finish the season World No.5.
The 2010–11 season was a dry spell for Reshetnikov, whose best individual result was a quarter-final lost 14–15 against Gu Bon-gil at the World Championships in Catania. With the team he won a bronze medal at the European Championships in Sheffield and Russia kept their World title after crushing Belarus 45–29 in the final.
In the 2011–12 season Reshetnikov took a silver medal in the Warsaw Grand Prix after being defeated in the final by teammate Aleksey Yakimenko. He was stopped in the first round by Ukraine's Dmytro Boiko in the European Championships in Legnano. In the team event Russia defeated Ukraine and Italy to meet Romania in the final. Reshetnikov won each of his three bouts, contributing to his team's 45–42 victory. At the 2012 Summer Olympics, he was defeated in the second round by Tim Morehouse of the United States. The team event proved equally disappointing as No.1 seed Russia was defeated by Romania in the semi-finals, then by Italia and went home with no medal.
In the 2012–13 season Reshetnikov won two silver medals in the Madrid and Padova World Cups. He sustained a hand injury in the Chicago World Cup which had him miss the rest of the season. At the European Championships in Zagreb he was stopped in the quarter-finals by teammate Nikolay Kovalev. In the team event, Russia fell in the first round against Ukraine and finished second-to-last. Two weeks later, despite tonsillitis, Reshetnikov took part in the 2013 Summer Universiade at Kazan where he took a bronze medal after teammate Aleksey Yakimenko defeated him in the semi-finals. In the team event Russia overcame the United States, China, Korea, then Italy to earn the gold medal. At the World Championships in Budapest, No.8 seed Reshetnikov disposed of Germany's Max Hartung in the quarter-finals, then of Romania's Tiberiu Dolniceanu. He fenced teammate and close friend Kovalev in the first all-Russian final in the major event since the Pozdnyakov v Sharikov duel in the 1996 Summer Olympics. Kovalev took the lead at the end of the first period, but Reshetnikov came back to win the World title. In the team event, Russia made their way easily to the quarter-finals, where they defeated Germany, then South Korea. They fenced Romania in the final. Reshetnikov opened the match, but was defeated 1–5 by Romania captain Dolniceanu. He won 6–4 his next bout against the youngest Romanian, Iulian Teodosiu. Russia eventually prevailed 45–38, allowing Reshetnikov to win a second gold medal. He finished the season No.1 in world rankings.
In the 2013–14 season Reshetnikov climbed the podium in the Moscow and Athens World Cups. He was seeded No.11 after the pools stage in the European Championships and made his way to the final, where he was defeated 15–11 by teammate Aleksey Yakimenko. In the team event, No.1 seed Russia had a tight 45–44 over No.9 seed Ukraine in the quarter-finals, then prevailed 45–41 over Belarus to meet Italy in the final. After a very tight match Reshetnikov was poised for the win on 43–44 in the last relay, but Italy's Luigi Samele struck two hits in a row to snatch the gold medal from Russia. In the World Championships in Kazan, Reshetnikov suffered front leg and back injuries and was defeated in the second round by Korea's Won Woo-young and could not defend his title. In the team event, defending champion Russia were defeated in the semi-finals by Germany. They fenced Hungary for the bronze medal, but were defeated and came away with no medal.