NANTERRE, France -- China stunned the U.S. by winning gold in the men's 4x100 medley relay on Sunday, a race the Americans had won at every Olympics other than the boycotted Moscow Games in 1980.

The medley relay was added to the program in 1960.

The winning team included Qin Haiyang and Sun Jiajun, who were both among the nearly two dozen swimmers who tested positive for a banned substance at the Tokyo Games but were allowed to compete after a Chinese investigation ruled that they consumed food that had been contaminated. The result is sure to stir more hard feelings from other nations that feel the Chinese got away with cheating.

But the real star of the Chinese team was Pan Zhanle, who had previously set a world record while winning the 100 free and powered away from American Hunter Armstrong on the anchor leg to touch in 3 minutes, 27.46 seconds.

The Americans had to settle for silver in 3:28.01, with France taking bronze in 3:28.38 to give Léon Marchand his fifth medal of the games to go along with four individual golds.

THE CLOSEST OF FINISHES.

Team USA finishes with SILVER in a thrilling men's 4x100m medley relay!#ParisOlympics | NBC and Peacock pic.twitter.com/2pE99yOJkI

NBC Olympics & Paralympics (@NBCOlympics) August 4, 2024

British star Adam Peaty, whose team barely missed out on a medal by finishing fourth, blasted a system that allowed the Chinese swimmers to compete at the Olympics.

"If you touch and you know you're cheating, you're not winning, right?" Peaty said. "As an honorable person, I mean, you should be out of the sport, but we know sport isn't that simple."

Peaty noted that after the initial revelations, additional reports surfaced of more positive tests in the Chinese program that went unpunished. The New York Times reported last week that two more Chinese swimmers had tested positive, including one 2024 Olympian, for a banned substance in 2022 but were cleared by Chinese officials to compete.

"I think we've got our faith in the system, but we also don't," he said. "Whoever's in the race, I expect in my head that it has to be fair for them to be there. We did our best job as a team to do that, and it may have been [worthy of] a bronze. Who knows?"

Caeleb Dressel, who swam the butterfly leg for the Americans, said prior to the Olympics that he didn't have faith in the World Anti-Doping Agency or his sport's governing body, World Aquatics.

With a silver around his neck, he seemed resigned to the belief that nothing will change.

"I don't work for WADA," Dressel said. "There's nothing I can do."

Swedish gold in the women's 50 free

Sarah Sjöström of Sweden claimed her second gold medal of the Paris Olympics, furiously dashing from one end of the pool to the other to easily claim the 50-meter freestyle title on the final night of swimming Sunday.

Sjöström, 30, competing in her fifth Summer Games, had already won the 100 free -- an event in which she holds the world record but only decided to swim at the urging of her coach.

She was more surprised than anyone with that victory, which had her overflowing with confidence heading into the 50 free.

Sjöström touched in 23.71 seconds, just shy of the world record of 23.61 she set at the 2023 world championships in Fukuoka, Japan. In a race that's usually decided by a hundredths of a second, the Swedish star turned this into a relative blowout. She was fastest off the block and clearly in control by the midway point of the single lap.

Meg Harris of Australia took the silver in 23.97, while the bronze went to China's Zhang Yufei in 24.20. For Zhang, one of the swimmers implicated in a Chinese doping scandal, it was her fourth bronze of the games to go with a silver.

Gretchen Walsh of the United States just missed out on her fourth medal of the games, touching fourth in 24.21.

In the last individual event, Daniel Wiffen of Ireland was looking to add the 1,500 freestyle title to his victory in the 800 free.

The competition at La Defense Arena was set to close with the men's and women's 4x100 medley relays.

The Associated Press contributed to this story.