“It is not like he is winning races; he is dominating races,” Scott said. “He almost finished the week with a world record. And to do it in France too – as much as what Phelps did was pretty sensational – he never did it in his home country.

“He is becoming a global superstar now. He kind of runs France.”

‘The greatest double’

When Marchand walked onto the pool deck, he received a rapturous greeting from the crowd and a double thumbs-up from President Emmanuel Macron. After he touched the wall first in 1:54.06 – a time that eclipsed Phelps’ Olympic record and gave the world record a nudge, he held up four fingers, and the stadium went nuts.

Phelps was commentating for American broadcaster NBC two nights earlier when Marchand became the first swimmer in nearly 60 years to win two individual events on the same day of competition. He described it as “the greatest double I’ve ever seen in the history of the sport.”

Marchand is just the fourth swimmer, along with Americans Mark Spitz and Phelps and Germany’s Kristin Otto, to win four individual events at the same Olympics. He said it felt crazy to be in the company of such giants of the sport, but chasing Phelps’ astonishing career feats is part of Marchand’s grand plan.

“Michael is a swimming legend,” he said. “I am always really proud when someone compares me to MP. I have been watching so many races … I have been learning from his coach the last three years. I know how coach Bowman was working with him and I think we are trying to do the same.”

In a week of near-perfect swimming, Marchand book-ended a brace of golds in the 200m butterfly and breaststroke with emphatic wins in the 400m and 200m individual medleys. Bowman thinks that as Marchand becomes older and stronger, he will add the shorter distances in the breaststroke and butterfly and perhaps some freestyle events.

‘An ability to feel the water’

Part of the Phelps legend was his unique physiology, with an arm span greater than his height, an unusually long trunk, and large hands and feet. If Leonardo da Vinci had sketched the ideal butterfly swimmer, he would have come up with someone shaped just like Phelps.

And Marchand? “Obviously, Léon’s parents were Olympic swimmers, so there is something,” Bowman said. “Michael didn’t have that.

“He has an ability to feel the water. He is built very hydrodynamically and super-good underwater.

“The thing they both have is work ethic second to none and the ability to come in, day in and day out, and consistently perform in practice.”

To be an Olympic champion medley swimmer, you can’t have a weak stroke. Marchand’s secret power is what swimmers call the fifth stroke – the turns and underwater work that complete the aquatic package.

When Marchand was swimming his way through college America, mostly in 25m pools, a local journalist noticed the kid from Toulouse seemed to be spending most of his races underwater. When the journalist pointed this out, Marchand smiled and explained it was deliberate. “I am moving way faster underwater than on the water,” he said.

The French Swimming Federation calculated earlier this week that during Marchand’s 400 IM final, he spent 103m of the race underwater. To appreciate why, you only need to look at underwater footage of how Marchand’s dolphin kicks propel him out every turn.

As Bowman knows from his many years coaching Phelps, things will also move fast out of the water for France’s new sporting star. “Léon is going to go out in this environment in a very different life situation than he was before, with a lot of different people,” Bowman said.

“There will be a lot of things that have nothing to do with swimming and a lot about making money and other things. And then, at some point, I’ll try to reel him back in, and in six weeks or so, we’ll see if we can get him started.”

But for now, he gets a break. And it will be fun. “Oh my god, it is going to be fun.”