Norway's Karsten Warholm extended his dominance in the men's 400m hurdles by digging deep to win his third world title in Budapest on Wednesday.

Olympic champion Warholm clocked 46.89sec for gold, with Kyron McMaster of the British Virgin Islands taking silver in 47.34sec.

American Rai Benjamin claimed bronze in 47.56sec as defending world champion Alison Dos Santos of Brazil hit the third-last hurdle and saw his chances of a podium place evaporate, finishing fifth.

Warholm, who set the world record of 45.94sec in winning Olympic gold in Tokyo two years ago, started in his favoured lane seven, outside Benjamin. McMaster was drawn in lane eight and Dos Santos in nine.

With such heavy-duty traffic around him, Warholm was unable to break clear of the field, as he often does against lesser competitors.

Indeed, at one stage it looked like Benjamin was gaining on Warholm, the pair going over the seventh of the 10 hurdles stride for stride.

Dos Santos rattled that hurdle to effectively end his medal hopes and then Warholm dug deep.

Face grimacing and every tendon screaming, Warholm produced a massive effort to go a metre clear as the field entered the home strait.

In what was arguably one of his ugliest displays of hurdling, the Norwegian clawed his way to the line to ensure a third world gold.

As Benjamin began to tire after his earlier efforts, McMaster came through for a memorable silver.

Warholm had previously won world golds in London in 2017 and Doha in 2019. Returning prematurely from injury, he could only finish seventh in Eugene last year.

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