Swimming: China end US reign over men's 4x100 medley relay at Paris Olympics

The United States' 64-year unbeaten run in the men's 4x100 metres medley ended at the Paris Olympics on Sunday as China swept to a seismic win at La Defense Arena.

Amid deafening cheers at the converted rugby stadium, the 100 metres freestyle world record holder Pan Zhanle brought China home with an outrageous swim as he, Xu Jiayu, Qin Haiyang and Sun Jiajun won in a time of three minutes, 27.46 seconds.

Caeleb Dressel and the Americans took silver, 0.55 seconds behind the Chinese, while a Leon Marchand-powered France grabbed the bronze, finishing nearly a second behind.

"Today China was just a little bit better. I think all of us going in, we're putting a lot of pressure on ourselves to be great out there... So hats off to China, they did a great race tonight," American Ryan Murphy told reporters.

The U.S. did not compete at the 1980 Moscow Games due to a boycott, but they had never been beaten in the men's medley final dating back to the inaugural event at the 1960 Rome Games.

Pan will take enormous credit for defeating them as he celebrated his 20th birthday in style, rocketing to the wall in 45.92 seconds.

"That was a monster split for Pan... so that's a pretty cool birthday present," Hunter Armstrong said.

"This is my first time anchoring a relay for Team USA and it carries a bit of pressure, but we each just get in and we do the best we can."

Qin, who swam the breaststroke leg, was also important with a sizzling time of 57.98 to upstage France's four-gold hero Marchand.

"This medal has the same flavour than the others, except that it's shared... It's the cherry on the cake and I will remember it because we had a super team," Marchand said.

"I did something crazy, I'm so happy. What I've done is incredible. I came for one medal and I go back with five."

Chinese swimmers have been under intense scrutiny since revelations in April that 23 of them tested positive for a banned heart medication before the 2021 Tokyo Olympics but were allowed to compete.

The World Anti-Doping Agency (WADA) accepted the findings of a Chinese investigation that the results were due to contamination from a hotel kitchen, and an independent review backed WADA's handling of the case.

However, Britain's Adam Peaty said he had no faith in the system after his team came fourth to miss out on the podium. Dressel said they had to put their trust in the World Anti-Doping Agency (WADA).

"I honestly haven't paid too much attention to it, because a lot of that is out of my control. I don't work for WADA, there's nothing I can do," Dressel said.

"That was a close race, it came down to the wire. They had four great splits, we had four great splits, and they were faster - simple as that."