Noah Lyles was given a wheelchair after competing in the men's 200m final.

It's not how he thought the event would end.

The first sign of trouble on Thursday night came when Noah Lyles started rounding the curve in the Olympic final of the 200 metres—the sprint that has always been his best race.

Normally at the curve, Lyles starts making up ground, then pulling away from what have been, for the last three years, game but overmatched contenders.

Instead of Lyles reeling in the runner two lanes to his right, Letsile Tebogo of Botswana, Tebogo pulled farther away.

The American favourite, who had gone three years without losing in the 200m dash, laboured to the finish and collapsed on the track after finishing third.

The insidious spectre of COVID, the killer virus that upended the globe four years ago and made the last Olympics part of its collateral damage, struck at the Paris Games, too.

In a bracing reminder that the virus is still very much a factor, even if its deadly fingerprint has been blunted, the world's marquee sprinter, racing on the world's biggest sports stage, revealed he had tested positive two days before his shocking, but now not-inexplicable, bronze-medal finish in the 200m.

Noah Lyles showed no signs of illness before the men's 200-metre race, other than the addition of a face mask.

'I still wanted to run,' Lyles said, wearing a mask, as he spoke to reporters, whose mere congregation in a jam-packed scrum underneath the stadium was unthinkable three years ago at the delayed Tokyo Games.

With the blessing of officials at USA Track and Field and the US Olympic and Paralympic Committee, who said they followed protocol, Lyles did run.

Lyles's US teammate Kenny Bednarek finished second, marking the second straight Olympics in which he and Lyles finished 2-3.

Coming into Paris, Lyles, the three-time world champion with the American record and the world's best time of 2024 on his resume, had seemed like as sure a thing in the 200m as any single athlete at track this side of Sydney McLaughlin-Levrone.

After opening with a scintillating win in the 100m four nights earlier, he was trying to become the first man to complete the 100-200 double since Usain Bolt eight years ago.

A troubling sign, however, came the night before when Lyles finished second in his semifinal heat, also to Tebogo.

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It marked the first time he had lost a 200m race of any sort since his disappointing third-place finish in Tokyo.

He also hurried out of the stadium after that loss and went to the medical tent—a rare occasion when he didn't stop to talk to reporters.

Usually one of the most energetic runners on the track, both before and after any sprint, Lyles collapsed, rolled onto his side and gasped for breath.

'But I mean, to be honest, I'm more proud of myself than anything for coming out and getting the bronze medal with COVID.

'We acknowledge Aboriginal and Torres Strait Islander peoples as the First Australians and Traditional Custodians of the lands where we live, learn, and work.

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