The Russian -- defending the 75kg Greco-Roman title he won at London 2012 -- battled back after blacking out during his semifinal against Croatian Bozo Starcevic.
With Vlasov in a comfortable lead, Starcevic clamped an arm around his neck before pinning him to the mat, with the Russian later claiming his opponent had "strangled" him.
Officials -- who signaled Starcevic's move was legal by awarding him two points -- stopped the bout when they realized Vlasov had blacked out.
But within moments, the 25-year-old came round before getting back to his feet and completing victory.
And on Sunday, he rounded off an extraordinary story by comprehensively defeating Denmark's Mark Madsen in the gold medal showdown.
Vlasov told reporters he had been motivated to win because "we all understood that we have to get as many gold medals as possible as a consequence of the situation around sports in Russia."
He hit out at the ban on Russian athletes
, after an investigation into allegations of systematic, state-backed doping, as "unfair."
Looking back on his semifinal, he said: "The opponent even strangled me -- but the judge didn't even give him a warning.
"Thank God I was allowed to continue to the end and win this match. I had to pull myself together and I tried to tune it out, because something like that had never happened before.
"I realized that it was not over yet, and I had to fight on. I was unconscious when he strangled me, but I came out of it right away."
Vlasov, a lieutenant in the Russian army, said he had beaten a "very strong" Madsen in the gold medal match and added: "I have fought him six times, and he has studied me thoroughly.
"He hit me hard -- I do not know how I managed to stand up but, thank God, I did."
And he stressed that he hoped his win would serve as an inspiration to the country's other wrestlers, adding: "I am sure they watched and supported me, and that this victory will give them confidence."