Favourite Grant Holloway said nerves got the better of him after finishing second to Jamaica's Hansle Parchment in the men's 110 metres hurdles Olympic final.
The American led at the halfway mark but faded over the final 20 metres as he was beaten by his 31-year-old rival.
Parchment triumphed with a season-best time of 13.04 seconds, ahead of Holloway in 13.09, lucky to scrape ahead of Jamaican Ronald Levy who took bronze with 13.10.
Holloway and Parchment had run in the same heat and semi-final prior to the final, with the American winning both, before falling short in the all-important race.
"I think the anxiousness and the nerves got the better of me towards the end and I got sloppy with my form," Holloway said. "He got me this time but I'll make sure I get him in the next."
He added: "Hats off to Hansle for an amazing race. I was watching him when I was in high school. He's a hell of a competitor. He has an amazing race plan, he executed to the best of his ability."
Parchment admitted he learned from losing to Holloway in the previous two runs.
"I made some changes to my start, because I knew if I was going to catch up, I had to be closer in the first half," Parchment said. "I think I ran through pretty well. I maintained composure. It was a great race."
Portugal's Pedro Pichardo earned gold medal glory with a national record 17.98m in the men's triple jump.
Pichardo's triumphant effort came with his third attempt, while China's Zhu Yaming claimed silver with a personal best of 17.57m. Burkina Faso's Hugues Fabrice Zango took the bronze with 17.47m.
USA's defending champion Ryan Crouser threw an Olympic record 23.30m to win the men's shot put gold.
Crouser bettered the Olympic mark he set five years ago in Rio de Janeiro to win from countryman Joe Kovacs (22.65m), while New Zealand's Tomas Walsh (22.47m) claimed bronze.
EARLY SCARE AS USA REACH FINAL
The United States trailed by 15 points in the second quarter against Australia but rallied to qualify for the men's basketball gold medal match.
USA won 97-78 over Australia, who have never won an Olympic medal in men's basketball having finished fourth four times.
The Boomers had raced to a commanding position early on as Team USA struggled from beyond the arc.
Yet the reigning Olympic champions reduced the margin to three points by half-time and went up several gears with a 32-10 third quarter.
Brooklyn Nets star Kevin Durant top-scored again with 23 points and nine rebounds, while Devin Booker had 20 points.
USA will face either France or Slovenia in the final as they chase a fourth straight gold medal.
CARRINGTON MAKES NEW ZEALAND HISTORY
New Zealand's Lisa Carrington added a third Tokyo 2020 gold medal to her haul, landing the title in the women's kayak single 500m final.
Carrington claimed her fifth-ever Olympic gold with a strong victory in 1:51.216, from Hungary's Tamara Csipes and Denmark's Emma Jorgensen.
She becomes the first athlete from New Zealand to win five Olympic gold medals, surpassing the four of Ian Ferguson, also in canoe sprint between 1984 and 1988.
Carrington is the fourth woman at Tokyo 2020 to win three gold medals, after Australian swimmers Emma McKeon (four) and Kaylee McKeown (three) and South Korean archer An San (three).
GERMAN ADDS GOLD IN OPEN WATER
After winning bronze in the 1,500m in the pool, Germany's Florian Wellbrock won the men's marathon swimming in open water.
Wellbrock won in one hour, 48 minutes and 33.7 seconds across 10 kilometres, finishing 25.3 seconds ahead of Hungary's Kristof Rasovszky for silver, with Italy's Gregorio Paltrinieri earning bronze.
The size of the German's victory was the biggest margin in Olympic marathon swimming history.
“It’s a little bit unreal," Wellbrock said. "The first seven (kilometres) of this race felt really easy."
AUSSIE SKATEBOARDING WINNER
Keegan Palmer won Australia's first-ever skateboarding gold medal with two amazing runs in the men's park final.
The 18-year-old's first run scored 94.04 before a throwaway second round. Palmer backed it up on his final run with a staggering top score of 95.83.
Brazilian Pedro Barros was next best with 86.14 for silver, while Cory Juneau claimed bronze with 84.13.
The event was the final skateboarding medal opportunity from the sport in its debut Olympics.