PARIS, France (AFP) — French hero Leon Marchand cemented his Paris Olympics legacy with a fourth swimming gold of the Games while Australia’s Kaylee McKeown made a slice of history, but it was a disastrous day for American superstar Caeleb Dressel.

Marchand was little known outside the swimming world before these Olympics, but he has become a national and international phenomenon in the space of a week with a quartet of titles.

With the 400-meter medley, 200m butterfly and 200m breaststroke already in the bag, the 22-year-old rose to the occasion again in front of French President Emmanuel Macron in the 200m medley at a deafening La Defense Arena.

Roared on by a partisan home crowd, he hit the wall first in one minute and 54.06 seconds — the second fastest time in history -- to ensure he will leave the Games as one of its biggest stars.

“It’s only the beginning. I’m really excited — my next goal is LA,” he said, referring to the 2028 Olympics in Los Angeles.

“Last night, I slept like 11 hours. I was just so tired.”

“But this morning I woke up, I was full of energy again. I don’t think anything went wrong this week. It was just perfect.”

McKeown, 23, did not generate quite the same reception but her feat was also exceptional.

She held off American arch-rival Regan Smith to win the 200m backstroke in an Olympic record 2:03.73, on the back of her 100m victory, to remain flawless over two Olympics with four golds from four individual events.

No Australian swimmer, man or woman, has ever completed a “double-double” — defending two different individual Olympic titles.

Her teammate, Cameron McEvoy, thundered to the men’s 50m freestyle gold in 21.25sec, with defending champion Dressel only managing sixth.

Dressel, who won five golds at the Tokyo Games in 2021, returned to the pool but failed to qualify for his 100m butterfly title defense.

Five-time world champion Marchand went into his race as favorite and with fans ready to accept nothing less than victory, he emphatically delivered, just missing Ryan Lochte’s 13-year-old world mark.

China’s Wang Shun powered ahead after the opening butterfly leg, but Marchand then switched through the gears to assume control, with Macron on his feet pumping his fist in celebration at the finish.

Defending champion Wang came third, with Tokyo silver medallist Duncan Scott of Britain second again.