Bol, second at last year's worlds and third at the 2020 Tokyo Olympics, was level with American Shamier Little until just before the home straight but pulled away emphatically to cross the line well clear in 51.70 seconds.

It was a hugely satisfying win for Bol, who was in tears after falling metres from the line when racing for gold in the 4x400m mixed relay on the opening night of the championships.

"It wasn't easy to forget what happened in the final metres of the relay but my team was around me and they put me at my ease," said Bol, who covered her eyes in disbelief after crossing the line on Thursday.

"I took the first few hurdles fast and then I could run my rhythm," Bol said of her strategy.

"I think I have just had the best first 200 metres ever. Then I just needed to finish the race which I could do easily."

Little came second in 52.80, just holding off Jamaica's Rushell Clayton who took the bronze in 52.81.

"I feel as if the hard work has paid off. I'm thankful and happy," Little said.

"I've been working on controlling my nerves a lot. So to come here in this noise and not let it faze me, and not let the heat get to me, that was an achievement. I really am just proud."

Bol had been a second faster than anyone this season, clocking a personal best of 51.45, and had won 28 of 30 races coming into the championships.

"I knew that 400 metres hurdles would be a chance to show up and I was confident," she said.

"Altogether I can say that this was a very good season."