Roared on by a delirious crowd at La Defense Arena, Marchand took down Michael Phelps's Olympic record from Beijing 2008 with a blistering swim of one minute 54.06 seconds, 0.06 seconds short of Ryan Lochte's world record.

"It was my last individual final so I said to myself, I really have to enjoy it," Marchand told reporters.

"I had a lot more energy than yesterday so I felt better, more relaxed.

"And I really wanted to have fun in my last final and it happened, so it was huge."

Britain's Duncan Scott won the silver, more than a second behind Marchand, while China's defending champion Wang Shun took the bronze.

The win made Marchand the first French athlete to take four individual golds, as opposed to team ones, at a single Summer Games and only the third male swimmer to do so after Americans Michael Phelps and Mark Spitz.

After touching the wall to deafening cheers, Marchand held up four fingers as President Emmanuel Macron raised his arms and punched the air from the terraces.

"FRENCH MICHAEL PHELPS"

France's first swimmer to win a medley gold, Marchand triumphed nearly 30 years after his father Xavier became the first Frenchman to reach an Olympic final at the 1996 Atlanta Games.

He won the 400 Individual Medley last Sunday and then both the 200 butterfly and 200 breaststroke within two incredible hours on Wednesday.

Just as he had done three times before, the 22-year-old from Toulouse mounted the podium and belted out the Marseillaise with the entire stadium accompanying him.

"Leon's name's now in the national anthem it seems, which is pretty cool," said Scott, who extended his British record haul to eight Olympic medals.

"As much as what Phelps did was pretty sensational, he never did it in his home country and so he's becoming a sort of global superstar now. He kind of runs France now."

The great expectations might have been too much for other swimmers at their home Games but Marchand only drew energy from them as he lived up to his nickname the "French Michael Phelps".

Coached by Bob Bowman, the man who helped Phelps to greatness, Marchand was asked if he was comfortable with comparisons with the American great and replied: "He’s a legend of the swimming world and he will always be."

"I met Michael last year. He was an amazing guy to me," he added.

"He gave me a lot of advice... I don't know. It's just crazy to be compared to those guys."

It was certainly a Phelps-like performance in the 200 IM final.

Marchand took control from the second backstroke leg, stretched his lead through the breaststroke as French fans grunted in unison, then powered home in the freestyle to give the world record a shake.

At 22, the future is bright for the face of the Paris Games.

"It's not over for me," said Marchand. "This is just the beginning. I'm really excited. My next goal is the LA '28."