Britain's Adam Peaty was denied in his bid to became the first person to win three consecutive 100m breaststroke titles at the Olympic Games, finishing joint second with America's Nick Fink in a time of 59.05 seconds at La Defense Arena in Paris.

Top honours went to Italy's Nicolo Martinenghi who was only 0.02 seconds faster than the Brit and American in a relatively slow final.

Earlier, the second night of swimming got off to a great start for hosts France as swim star Leon Marchand dominated the field in the men's 400m individual medley to win in a new Olympic record time of 4 minutes, 02.95 seconds, just shy of his world mark of 4 minutes, 02.50.

Marchand was ahead as soon as his head popped from the water and he steadily pulled away from the field in what was essentially two separate races: Marchand racing the clock and everyone else competing for silver and bronze.

The silver went to Japan's Tomoyuki Matsushita, who finished nearly 6 seconds behind the winner in 4 minutes, 08.62 seconds. American Carson Foster claimed the bronze a fraction of a second behind.

"It was crazy. I think I will remember this one for a very long time," said Marchand.

"The emotions are very difficult to describe. It was incredible for a swimmer. I opened my eyes, listened to everything that was happening around. And that really pushed me to already have a great race and have a lot of fun."

Afterwards, it was a US one-two in the women's 100 metres butterfly as Torri Huske stunned her American teammate and world-record holder Gretchen Walsh to clinch the gold medal.

Walsh turned first, but Huske came home strongly to touch in 55.59 seconds, with Walsh second in 55.63 and China's Zhang Yufei taking bronze in 56.21.

"I don't really remember my race that much. My first 50 felt good, and then I've been really working on my second 50 a lot, especially after last year," said Huske.

Canadian defending champion Maggie Mac Neil finished fifth and Australia's Emma McKeon, the queen of the pool in Tokyo with seven medals, came sixth.

In semi-final action, China's Tang Qianting is ranked fourth going into the women's 100m breaststroke final later on Monday while Yang Junxuan is fifth seed going into the women's 200 free. On the men's side, Xu Jiayu qualified first in the 100m backstroke. (Agencies)