By Harry Poole, BBC sport journalist at Stade de France
Botswana's Letsile Tebogo claimed a surprise Olympic 200m gold medal as Noah Lyles was denied a sprint double at Paris 2024.
Tebogo, 21, stormed clear of his rivals to clock an African record of 19.46 seconds and finish ahead of American Kenneth Bednarek, who crossed the line in 19.62.
Lyles, crowned the world's fastest man by five-thousandths of a second in a historically quick 100m final on Sunday night, was unable to compete at the head of the race and matched his Tokyo bronze in 19.70.
It emerged after the race that Lyles had tested positive for Covid and the 27-year-old had to be helped off the track in a wheelchair.
Having burst out on to the track to huge cheers before the race, Lyles was seeking to become the first man since Usain Bolt in 2016 to complete a 100m and 200m double at an Olympic Games.
But Tebogo had other ideas.
A world bronze medallist over the distance last year, Tebogo also took 100m silver in Budapest as Lyles completed a golden treble.
That was a dazzling return for Tebogo at his first global championship, but it was nothing compared to his achievement at the Stade de France as he marked his first Olympics with a gold.
Tebogo, sixth in the Paris 100m final, lined up with a 200m personal best of 19.50 - notably down on the favourite's 19.31.
Showman Lyles made his entrance to huge excitement, seemingly ready to seize his moment with the eyes of the world fixed upon him, but he remained third throughout following a slow start.
Bednarek held out to equal his silver of three years ago in Tokyo - a medal he also won at the 2022 World Championships - but could not overhaul Tebogo.
Tebogo stars as illness wrecks Lyles' hopes of history
Tebogo dedicated Olympic gold to his mother Seratiwa, who died in May of this year after a brief illness, and held his spikes, displaying her date of birth, up to the camera following his victory.
"It's basically me carrying her through every stride that I take inside the field," Tebogo said.
"To take her [with me], it gives me a lot of motivation. She's watching up there, and she's really, really happy."
Having ended Lyles' 26-race winning streak over the distance in the semi-finals, Tebogo announced himself on the global stage as he repeated that victory over the man who has long been tipped as Bolt's heir apparent.
Tebogo entered the home straight with an advantage and, as his rivals threatened to pull alongside, he surged away in the closing stages to clinch an emotional - and hugely significant - triumph.
Lyles, the fastest man over 200m this year before this race and a three-time reigning world champion over the distance, produced his usual theatrics before the serious business began.
But this performance in his favoured event was not at his usual world-beating standard and it soon became apparent why as news broke of the American's illness.
Bolt, the fastest man in history and winner of eight Olympic gold medals, completed the sprint double at three successive Games in Beijing, London and Rio - and he remains the only man to ever enjoy such a dominant streak.
Lyles had targeted a remarkable four golds in Paris, including both the 4x100m and 4x400m relays, but it remains to be seen whether he will be fit to contest those finals.
- BBC