TOKYO, Aug 3 ― World champion Noah Lyles endured a finish-line gaffe to qualify from today’s semi-finals for the Olympic 200 metres final.

The 24-year-old inexplicably slowed up with 10 metres of his semi to run and was promptly overtaken at the line by Canada’s Aaron Brown and Liberian Joseph Fahnbulleh, all three credited with 19.99sec.

It meant Lyles didn’t qualify automatically as one of the first two finishers, instead handed an anxious wait as the third and final semi-final went ahead.

That was won in some style by Brown’s teammate Andre de Grasse, the Rio silver medallist, who clocked a national record of 19.73sec ahead of American Kenneth Bednarek, in 19.83.

Lyles qualified as one of the next two fastest, along with Jereem Richards of Trinidad and Tobago.

"It is not a win-lose situation,” Lyles insisted. "I’m glad I made it to the finals and that is all that matters.

"I knew I was going to make it. It was a bit risky, I wouldn’t lie, but I made it.”

De Grasse said he had not expected to go that fast.

"I wanted to save it for the final but Kenny (Bednarek) was pushing me a little so I had to make sure I qualified for the final,” the Canadian said.

"It’s super-fast,” he added of the track. "I think tomorrow night we are going to see some fast times in the men’s 200m as well.”

US teen sensation Erriyon Knighton won the opening semi-final convincingly in 20.02sec, scoring a psychological blow by casually looking across the field no less than four times on the back stretch through to the line.

The 17-year-old will become one of the youngest ever 200m finalists when he lines up at the Olympic Stadium tomorrow. ― AFP