One more final, one more gold, and one more Olympic record for Léon Marchand. This one was in the 200m individual medley, and when it was all over, in 1min 54.06sec, the roars carried far and wide across the city, even delaying the track races six miles away at the Stade de France because the cheering for him there was so loud. Back at the swimming, Marchand was all of a sudden so tired he could hardly raise an arm to celebrate. He hung on the lane divider, smiling, then finally hauled himself out of the pool to salute the crowd.

It was Marchand’s 11th race in six days, his fourth gold, and his fourth record. Great Britain’s Duncan Scott was closest to him, but truth be told that wasn’t very close at all. Scott won the ­silver in 1min 55.31sec. It was his eighth Olympic medal. Only Jason Kenny has ever won more for Great Britain.

Scott’s was Britain’s second silver of the night, after Ben Proud won one in the 50m freestyle. It was a sweet relief for him. Proud, 29, had won two world titles, but had finished fourth and fifth in his last two Olympic finals. In Paris, he was 0.05seconds behind Australia’s Cam McEvoy, and if he felt a little regret immediately afterwards – “Maybe I’ll look back at the footage and kick myself a little bit because I could have been faster” – it soon gave way to satisfaction that he had won a medal at last. “It’s not gold but hey ho, I’m super happy.”

Scott was pretty phlegmatic, too. It was his second-fastest time ever. But Marchand was just that much faster. “I’d like to think I went head to head with Leon for a little bit of the race,” he said, “but the guy is the best 200m breaststroker in the world, the best 200 fly swimmer in the world, the best 200 medley swimmer in the world, and the best 400 medley swimmer in the world. It’s a real honour to be able to race him in this environment as well. The crowd were nuts. It was sensational to be a part of.”

Scott had finished second in Tokyo three years ago, too, and painful as it was for him to come runner-up again, it was some small consolation that he lost to one of the greatest to ever do it, and some small consolation, too, that he at least beat the man who had come in front of him last time, China’s Wang Shun. Wang, who finished third, is one of the 11 Chinese swimmers competing here in Paris who had previously tested positive for a trace amount of the banned performance-enhancer TMZ and been allowed to compete on the basis that the authorities were satisfied it was caused by food contamination.

For the briefest moment, it looked as though Wang might beat Marchand. He was ahead of him after the butterfly leg, and right behind after the backstroke, but Marchand pulled away from him, and everyone else, during the breaststroke. By the time those 50m were over, he was so far in front that there was no way anyone was going to catch him on the freestyle. Marchand’s breaststroke is one of the great sights of the Games. he has a lovely, long, languid stroke, which somehow makes it look like he’s moving slower than everyone else even while he’s racing out in front of them. It’s as irresistible as the tide.

The 200m medley was the one gold Marchand wanted most of the four this week. His mother, Celine, swam the 200m medley at Barcelona in 1992, and finished 14th, and so did his father, Xavier, at Atlanta in 1996, when he was eighth, and Sydney in 2000, when he was seventh. Emmanuel Macron came along to watch the kid do what his parents never could, and he was shouting and roaring along with the thousands of other French fans in the arena. Whatever happens next, Marchand is one of the single biggest reasons why these Games will be remembered as a success in France.

That said, his victory may not even have been the most popular medal the country won last night. Twenty minutes earlier, Florent Manaudou won the bronze in the 50m free, behind Proud and McEvoy. Manaudou, 33, is the oldest male swimmer competing here, and, though he’s just about to lose the title, the most beloved too. He won gold in this event in London, then the silver behind Anthony Ervin in Rio. Then he quit the sport in an existential funk and spent the next two years playing handball in the French second division, which is the sort of eccentric move that can endear you to the French public.

He was back for Tokyo, where he came second again, and after that of course he had to hang on for these Games here in Paris. “Honestly, the highlight for me was sharing the podium with Florent Manaudou,” said Proud. “This is the fourth time he’s made the podium, he’s completed the set, so when I saw his name up there I just thought ‘Jesus Christ, that’s amazing’.” Swimming has so often been overshadowed by athletics at the Olympics, but here in Paris, Marchand, Manaudou and the French have raised it to a level that has not been seen since Beijing in 2008, when Michael Phelps won those eight gold medals.

And fittingly enough, it was, of course, Phelps’ old Olympic record from those very same Games that Marchand beat here. The king is dead, long live the king.