“Allez!” they cried each time Léon Marchand’s head bobbed out of the water. “Allez!” they urged, as the man who will end up as France’s biggest star at this Olympics powered towards 400m individual medley gold. And each “Allez!” came with such a ­ferocity and force it seemed to make the temporary ­foundations around this pool tremble in excitement.

This was not a race, but an oblitera­tion. The 22-year-old ­Marchand is trained by Michael Phelps’s old coach, Bob ­Bowman, and there were echoes of the American great as he took ­victory by an astonishing 5.67sec. For good measure his time of 4min 2.95sec also broke the longest ­standing Olympic swimming record, set by Phelps in 2008.

Japan’s ­Tomo­yuki Matsushita was second, and ­Carson Foster of the USA took bronze.

Meanwhile, poor Max Litchfield was almost in tears again after ­coming fourth in the same race for a third consecutive Olympics, despite ­breaking his own British record. “I’ve given absolutely everything, emotionally, mentally, physically,” the Briton said. “I’ve swum a best time and it’s just tough. Just the wrong side of it again.”

But for the boisterous home crowd Sunday evening was all about Marchand. The Frenchman was already out of sight by halfway, after the butterfly and the backstroke. The only question was how quickly he would race to the finish. In the end he just missed out on breaking his own world record, but he was well inside Phelps’s old Olympic best.

Afterwards he was serenaded with huge cries of “Léon! Léon!” and a ­rendition of La Marseillaise that stirred the soul.

Marchand has pedigree that meant this performance did not come out of the blue. His mother, Celine, ­competed in the pool for France in the Barcelona Olympics, while his father, Xavier, swam in Atlanta in 1996 and Sydney in 2000. But it was Marchand’s decision to send Bowman an email in May 2020 that proved to be the defining moment of his career.

“Dear Sir,” it began. “I am a French swimmer, my name is Léon ­Marchand (18 years old). I would like to join the university of Arizona State in summer 2021 for swim and compete in NCAA with your amazing team. Do you think I could benefit from a scholar­ship?” Bowman wrote back, saying he had “a particular fondness for the 400 IM” and the rest is history.

Now the big question is how many other medals Marchand might win at these Games. Most think that the 200m individual medley and 200m butterfly are shoo-ins for gold. Do not put it past him to win the 200m breaststroke either, although Qin ­Haiyang of China is the favourite.

Certainly Litchfield is a believer. “I think he’s going to have an incredible week,” he said. On this evidence you would be mad to argue.

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