TOKYO : Olympic champion Rai Benjamin stormed to victory in the 400 metres hurdles in 46.52 seconds to finally clinch his first world championship gold medal on Friday after two silvers and a bronze.

The 28-year-old American, who had put on a golden crown following the finish, had a few nervous moments after initially being disqualified for crashing into the final hurdle and affecting other athletes.

Benjamin's appeal was quickly upheld, however, and he was restored to the top of the timesheet with World Athletics confirming he was the champion.

The American said he thought he might have stepped on the line when he was first told of the potential qualification.

"It was all fine in the end," he said. "It feels great. I am glad I finally got the job done. I got another individual medal under my belt, for which I am extremely proud.

"I think I did a good job. Unfortunately, I got really greedy in the end and that's why I hit the last hurdle."

Brazil's Alison Dos Santos briefly held another world title to go with his 2022 triumph after finishing second in 46.84, but was satisfied with silver.

"If nothing irregular happened, that's not how I want to win gold," he said. "I want to conquer the race. So I am not sad with silver, I am happy."

Qatari Abderrahman Samba took bronze in 47.06, while Norway's world record holder Karsten Warholm, who was gunning for a fourth world title, finished fifth in 47.58 behind Ezekiel Nathaniel (47.11).

NO COMPLAINTS ABOUT REVERSAL OF DISQUALIFICATION

Nathaniel said he had been told to stand by while the disqualification and appeal were sorted out but had no complaints about how it all washed out, even if he did not end up on the podium.

"It's a fair call," said the Nigerian. "He put in a lot of work to get that medal and if they are trying to rip off from that, I don't think that's fair. He didn't deliberately knock over the hurdle, that could happen to anyone."

The race pitted the fastest three men in the history of the one-lap hurdle against each other and Benjamin, Warholm and Dos Santos all exploded out of the blocks.

Benjamin had a clear lead as they came around the final bend with Warholm starting to fade and the American looked to be cruising to victory until his foot made contact with the final hurdle.

Warholm also had no problems with the reversal of the disqualification but was very unhappy with his race.

"I had something happen when I got out of the block, like a little strain in my left thigh," he said.

"I don't know if it's a hamstring or knee. Trying to hurdle with it wasn't good. I also crashed the third hurdle. I tried to push but it was just a terrible race. A disaster."

Benjamin survives DQ scare to finally clinch 400m hurdles world title