America's Nathan Adrian snatched gold in the final stroke of the men's 100 meters freestyle on Wednesday.
Adrian was third on the turn but stormed back to win in 47.52 seconds, one hundredth of a second ahead of James Magnussen of Australia, who claimed silver.
"I kinda touched well and 'oh, sweet, I've won' then there's 10 to 15 seconds," Adrian said.
"Holy crap, this is the Olympics. I've been watching this since I was a kid."
Magnussen said it was painful to miss out on gold by such a narrow margin.
"It hurts. I did my best tonight and it wasn't quite good enough. It's been a tough Olympics," he said.
"They say what doesn't kill you makes you stronger so hopefully I can come out of this a better swimmer but most of all a better person."
Brent Hayden of Canada got the best start but faded to settle for bronze in 47.80.
"Physically I wasn't feeling that bad but emotionally and spiritually I just had to show what I was capable of," Hayden said.
