The controversy overshadowed an incredible night in the pool, where Briton Adam Peaty became the first to swim the 100m breaststroke in under 57 seconds and Australian teen Ariarne Titmus ended Katie Ledecky’s reign in the 400m freestyle. Peaty has been hammering away at the ‘Magic 57’ mark over the last couple of years, setting a world record of 57.10 in Glasgow in 2018, and while he was confident he could always go lower even he was stunned at swimming 56.88 in the semi-finals. “It feels incredible. I’ve been chasing that for three years now, ever since I tou­ched the wall in Rio I knew I could go faster,” he said.

He was careful not to get carried away, however, with the small matter of Monday’s final still to take care of. I’ve come here to win a world title and that’s tomorrow and that’s still my main focus, so this was just a bonus and I’ll use this energy tomorrow.” Ledecky had been aiming for a fourth straight world title in the 400m and everything looked to be going according to plan as she powered into the lead, only for Titmus to claw back the deficit and hit the front over the final 50.

Sun, competing in South Korea despite the Court of Arbitration for Sport (CAS) set to hear a doping case against him, won a record fourth straight 400m crown with Horton, who beat him to the title at the Games, in second place.

The Australian, who labelled Sun a “drug cheat” ahead of that Rio final, stood motionless behind the runners-up spot at the podium, while Sun stepped forward to collect a 10th gold medal at the worlds and Italian Gabriele Detti picked up the bronze.

“Disrespecting me was OK, but disrespecting China was unfortunate,” Sun said. “I feel sorry about that.”