On the home straight, Wayde van Niekerk accelerated away from his 400m opponents, almost as though a sudden gust of South-Easter was at the back of the man from the Cape.
As they came out of the final turn, Kirani James of Grenada and LaShawn Merritt of the US were crowding him, gaining, barely a step behind. Then came that kick in the outside lane, and off he went, leaving them behind to break a record set by one of the greats of sprinting 17 years ago.
On the stop match 43.03 looked very close to the chasers who clocked 43.76 and 43.85. At that pace on Rio's Olympic track, though, it was some metres. It was a glorious win.
Gold, and a world record. What more could the 24-year-old have hoped for? He was at his very best at the right moment. Years of sprinting, discipline and all that preparation saw him peak on cue, and his family was there to see it. It was a perfect day.
With his record, South Africans knew Van Niekerk was a candidate for the podium. He was the first athlete to run 100m in under 10 seconds, 200m in under 20, and 400m in under 44 seconds.
He showed a glimpse of what was to come with a 400m silver at 2014 Commonwealth Games in Glasgow. Then came the world championship in Beijing last year.
In the Olympic build-up, he won the 200m at the Africa Championships in Durban, and was part of the 4x100 relay triumph.
One of biggest in the track pantheon, Usain Bolt, had seen Van Niekerk's talent, knew he was capable of Sunday night's triumph. Bolt's respect and warmth for the South African, his embrace of him and his family, were remarkable features of Van Niekerk's special night.
The Jamaican had matters to attend to, like hurtling for the third time to Olympic 100m gold, but he made time for the South African. Former record holder Michael Johnson's praise, too, enriched a pinnacle evening for Van Niekerk, and a memorable one for South Africa.