Noah Lyles finished second to last halfway through the 100m final before mounting a remarkable comeback in the 50m to claim historic gold in Paris.
Lyles never led until the final stages of a dramatic race in which the American overtook Kishane Thompson in a photo finish.
Thompson missed out by 0.005 seconds, despite the 23-year-old Jamaican running 9.79 in his Olympic debut in France.
It was a heartbreaking climax for Thompson, who took the lead 30 metres into the race and stayed in front until the final second.
Lyles, on the other hand, was last for the first 40 meters of the race, then moved up through the pack to claim a remarkable victory.
Noah Lyles never led until the final strides of a dramatic 100-meter final on Sunday.
The American went from last to first place in just 60m to win the gold medal in a time of 9.79.
The American was the slowest off the track and did not move up to seventh place until halfway through the race.
She eventually finished with a new personal best of 9.79.
Meanwhile, his teammate Fred Kerley held on to second place throughout the race until the final metres, when he moved into the bronze medal position.
The narrow margins separating the fastest men on the planet were laid bare in the race analysis, with just 0.12 seconds separating Lyles from eighth-placed Oblique Seville.
Lyles beat Kishane Thompson in a photo finish, with the Jamaican losing by 0.005 seconds.
It was the first time all eight men had dipped under 10 seconds in a wind-legal 100-meter race.
“It’s what I wanted, it’s a tough battle, they are incredible opponents,” Lyles said.
‘Everyone came prepared for the fight and I wanted to prove that I am the man among them all, I am the wolf among wolves.
The reigning Olympic champion, Italy’s Lamont Marcell Jacobs, finished fifth in 9.85 seconds. Lyles is aiming for another gold in Paris in the 200 metres and the relay.