China pulled off a stunning medley relay triumph while the United States produced a pair of world records on a gripping final day of swimming at the Paris Olympics on Sunday.

China clinched its second swimming gold of the Paris Games by winning the men's 4x100m medley relay final on Aug. 4. (Xinhua)

Xu Jiayu, Qin Haiyang, Sun Jiajun and Pan Zhanle won China's second swimming gold of the Games by powering to victory in the men's 4x100m medley relay final.

China finished in 3 minutes 27.46 seconds, more than half a second ahead of the United States' combination of Ryan Murphy, Nic Fink, Caeleb Dressel and Hunter Armstrong.

France's Yohann Ndoye-Brouard, Leon Marchand, Maxime Grousset and Florent Manadou took bronze, 0.92 seconds behind China.

The result broke the United States' run of 10 successive gold medals in this event dating back to the Los Angeles 1984 Games.

It was Pan's second gold in Paris to go with his 100m freestyle triumph.

"This is magic for me," said Pan, who celebrated his 20th birthday on Sunday. "We make a good team and we managed to get a great result."

Pan's time of 45.92 represents one of the fastest 100m freestyle splits in history while Qin also clocked a stunning 57.98 to out-swim French hero Leon Marchand in the breaststroke leg.

Xu, who swam the opening backstroke leg in 52.37, did not hide his delight at adding gold to his two silver medals in Paris.

"The whole Olympic Games journey for me is great. I am very satisfied," said the 28-year-old.

American Bobby Finke set a new world record as he secured his second consecutive Olympic 1,500m freestyle title.

Finke withstood challenges from Italian Gregorio Paltrinieri and Ireland's Daniel Wiffen to finish in 14 minutes, 30.67 seconds, eclipsing the previous record of 14:31.02 set by China's Sun Yang at the London 2012 Games.

Paltrinieri claimed silver in 14:34.55 and Wiffen bronze in 14:39.63.

"The world's getting faster, and I think it's a really good thing," Finke said of his new benchmark as he praised the level of competition at these Games.

"It's a really healthy thing for the sport. If one country is always dominating, I can't really sit there and say the sport is growing. As much as it sucks that we're not dominating any more, I think it's good for the sport, and it shows how far the sport has come."

Finke joins compatriot Mike Burton, Russian Vladimir Salnikov and Australian pair Grant Hackett and Kieren Perkins as the only multiple Olympic champions in this event.

The United States also set a new world record in the women's 4x100m medley relay final as Regan Smith, Lilly King, Gretchen Walsh and Torri Huske clocked 3 minutes, 49.63 seconds, breaking the country's own previous mark of 3:50.40 set in 2019.

Australia's Kaylee McKeown, Jenna Strauch, Emma McKeon and Mollie O'Callaghan took silver while China's Wan Letian, Tang Qianting, Zhang Yufei and Yang Junxuan pocketed bronze.

In Saturday's only other medal race at La Defense Arena, Sweden's Sarah Sjostrom bagged her third Olympic gold medal by winning the women's 50m freestyle final.

Sjostrom, who set a new Olympic record of 23.66 seconds in her semifinal on Saturday, touched the wall in 23.71. Australia's Meg Harris took silver and China's Zhang Yufei grabbed bronze.

The 30-year-old also won the 100m freestyle title in Paris to go with her 100m butterfly crown at the Rio 2016 Games.

"It doesn't get any better than this, this is the peak of my career for sure," Sjostrom said after the race.