Thomas Barr took a tumble in the Diamond League as Norway's Karsten Warholm set a world record in the men's 400 metres hurdles in Oslo.

Barr indicated afterwards that he was relatively unscathed - "body is all good, ego is bruised" - but the night belonged to the victorious Norwegian.

The 25-year-old twice world champion broke the record with a time of 46.70 seconds.

Warholm beat 1992 Olympic champion Young's mark of 46.78secs, which was set four years before the Norwegian was born and was the longest-standing record in men's track.

Warholm raced to an early lead and never let up as he was roared on all the way to the finishing line, which he crossed ahead of 2019 Pan American Games champion Alison dos Santos by more than six tenths of a second.

"I knew that I had a fast time in my body," said Warholm. "It might take another world record to win the Olympics."