US sprinter Manteo Mitchell suffered a broken leg when running for his team in Thursday's Olympic Games 4x400m relay semi-final, but still managed to finish his lap.
The US team finished second to the Bahamas in the heat in identical times of 2:58.87, the fastest time ever run in the first round of the relay at the Olympics.
The 25-year-old Mitchell had slipped on a stairway in the Olympic Village earlier this week, and that misfortune reared its head after just 100 metres of his one-lap run.
"Three days ago I was going up the stairs and I kind of missed one and landed awkwardly," Mitchell said.
"I got treatment and I was fine. I did workouts, and when I warmed up today I felt really well. I felt I could go 44 (seconds)-low.
"I got out pretty slow, but I picked it up and when I got to the 100m mark it felt weird. I was thinking I just didn't feel right. As soon as I took the first step past the 200m mark, I felt it break."
Mitchell added: "I heard it. I even put out a little war cry, but the crowd was so loud you couldn't hear it. I wanted to just lie down. It felt like somebody literally just snapped my leg in half.
"I knew if I finished strong we could still get it (the baton) around. I saw Josh Mance motioning me in for me to hand it off to him, which lifted me. I didn't want to let those three guys down, or the team down, so I just ran on it. It hurt so bad. I'm pretty amazed that I still split 45 seconds on a broken leg."
After the race, Mitchell was taken to the Athlete Village medical area, where his leg was x-rayed and diagnosed by team doctor Bob Adams as a break of his left fibula bone.
Team USA will announce the final line-up for the men's 4x400m final on Friday.