Shaunae Miller of the Bahamas won a dramatic gold medal in the women's 400m final at the 2016 Rio Olympics.
In a thrilling finish, Miller stumbled and then dived across the line as she edged out American world champion Allyson Felix to win in 49.44 seconds.
Felix took silver in 49.51 seconds with Jamaica's Shericka Jackson third.
"The only thing I was thinking was the gold medal and the next thing I know I was on the ground," Miller, 22, said. "It was just a reaction."
She added: "I've never done it before. I have cuts and bruises, a few burns."
"I don't know what happened," said Miller, who finished second to Felix at the World Championships in Beijing in 2015.
"My mind just went blank. I heard my mom screaming. When I heard her screaming, I was like, 'OK, I had to have won the race'.
A tearful Miller, flagbearer for her country at the opening ceremony, told reports: "It is such an emotional moment for me. Before I came into the race I told myself, 'This is the moment I've been waiting for' and I just gave it my all."
Her coach, Lance Brauman, added: "She gave everything she had and her legs gave out at the line. It was not intentional."
Felix, who won the 200m at London 2012 and has three relay gold medals, now has seven Olympic medals in total - more than any other woman in US track and field history.
The 30-year-old American, who failed to make the 200m team after injury affected her preparation for the US trials, said: "It hurts right now. I don't think I ever quite had a year this tough."