Beslan Mudranov won Russia's first gold medal at the Rio Games in judo and fired a warning shot that his country had plenty more to prove.
Mudranov's victory comes two days after Russia's judo team was officially cleared to participate in the Olympics after his country escaped a blanket ban over its doping record.
"There has been a lot of psychological pressure that our country Russia has been subject to. Here, to win a gold medal on the very first day, of course it means a lot for my country," Mudranov told reporters through an interpreter.
"Of course, our country will prove to everyone that we can win the gold, I'm pretty confident that this is not the last gold medal we have won," he said.
Mudranov's gold in the men's -60kg follows his compatriot Arsen Galstyan's triumph in the same weight class in London four years ago.
In a tense duel with Kazahkstan's Yeldos Smetov that went into "golden score" extra time, Mudranov threw Smetov to score a match-ending waza-ari and earn his first Olympic medal. Japan's Naohisa Takato and Diyorbek Urozboev of Uzbekistan took bronze.
The World Anti-Doping Agency had called for a total ban on Russian athletes in Rio in response to the independent McLaren report that found evidence of state-sponsored doping by Russian athletes at the 2014 Winter Olympics in Sochi.
Mudranov said such a ban would not have been right.
"The president of the International Olympic Committee (IOC), he should realise that it would be unjust for the athletes who have spent their entire life preparing for the competition - for some of them it would probably be the only Olympic Games in their life," he said.
Mudranov added that there had been some nerves amongst the judo team on the day of the IOC announcement but overall they had been confident they would be allowed to compete.
"We came here prepared and no one broke down under this psychological pressure," he said.