USA's Sydney Mclaughlin set a new world record in the women's 400m hurdles just before the Olympics.

TOKYO: The sixth day of athletics at the Tokyo Olympics takes place on Wednesday. AFP Sport looks at five stand-out events:

Men's 200m - Final

World champion Noah Lyles won't be taking any more chances after he survived a finish-line gaffe to qualify for the 200 metres final.

The 24-year-old slowed up with 10 metres of his semi left and was 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, and instead had an anxious wait as the third and final semi went ahead.

That was won in some style by Brown's teammate Andre de Grasse, the Rio silver medallist. Lyles qualified as one of the next two fastest, along with Jereem Richards of Trinidad and Tobago.

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.

Women's 400m hurdles - Final

After Karsten Warholm's thrilling world-record run in the men's hurdles on Tuesday, arguably one of the best Olympic races in living memory, fireworks are also expected when the women take to the track.