Jakob Ingebrigtsen of Norway broke the 28-year-old world record in the 3,000 meters by more than three seconds during a Diamond League meeting in Poland on Sunday.
Ingebrigtsen clocked 7 minutes, 17.55 seconds at the Silesian Stadium in Chorzow. It shattered the previous best mark of 7:20.67 set by Daniel Komen of Kenya in 1996 that had been the longest-standing men's athletics world record in individual track events.
It was the first of two world records set at the meet, as Sweden's Mondo Duplantis broke his own pole vault mark by clearing 6.26 meters.
Ingebrigtsen won gold in the 5,000 at the Olympic Games but lost his title in the 1,500 in Paris. Three days ago, he had exacted a small measure of revenge over American Cole Hocker by winning the 1,500 in Lausanne in 3:27.83, two weeks after Hocker shocked the Olympic field to win gold in Paris.
The 23-year-old Norwegian was in shock when he crossed the line Sunday and looked at his time, putting his hands on his head in disbelief. Ingebrigtsen received a check for $50,000 and posed with it in front of the clock.
"It feels special, amazing. I was hoping to challenge the world record here, but based on my training, I can never predict exactly what kind of time I am capable of," he said. "I would not have imagined I could run 7:17, though. At the beginning, the pace felt really fast, but then I started to feel my way into the race and found a good rhythm.
"[The] 3,000 is a tough distance. After four, five laps you feel the lactic acid, but you need to get going. The conditions were difficult with the heat today, but it is the same for everyone."
He finished ahead of a trio of Ethiopians, with Paris 10,000-meter silver medalist Berihu Aregawi second in 7:21.28, a personal best and the third-fastest time in history. Yomif Kejelcha was third.
"Now I want to challenge world records at all distances, but it is one step at a time," Ingebrigtsen said.
Botswana Olympic champion Letsile Tebogo won the 200 meters by 0.03 seconds ahead of the Dominican Republic's Alexander Ogando while American Kenneth Bednarek was third.
Other Olympic champions were beaten, with Emmanuel Wanyonyi coming second in the 800 meters behind Canada's Marco Arop, while American Ryan Crouser was second to compatriot Joe Kovacs in the shot put.
Tokyo Olympic high jump champion Gianmarco Tamberi failed to finish on the podium in Paris, but he put his poor performance behind him to win the event with a jump of 2.31 meters.
The Associated Press and Reuters contributed to this report.