Karsten Warholm was still patiently making his way through the media "mixed zone" more than an hour after his stunning, world-record-destroying run in the 400m hurdles on Tuesday, and still he seemed unable to absorb the enormity of his achievement.

It was hardly surprising. The Norwegian won Olympic gold in an incredible 45.94 seconds, taking almost a whole second off his own world record of 46.70 from last month in an event where progress is usually measured in hundredths. American Silver medallist Rai Benjamin was also miles inside the old mark in 46.17 as the race more than lived up to its Tokyo top billing.

"Man it’s so crazy. It's by far the biggest moment of my life," Warholm said. "You know the cliche that it hasn't sunk in yet? I don't think it has, but I feel ecstatic.

"I told myself going in to the race to remember all the work you have put in. I can't describe how important this is for me. This is what I do morning until night, it's huge.

"I dream about it like a maniac. I sleep all night on it. I spend all my time thinking about this, thousands of hours, so just getting this last medal into my collection, it’s complete."

Warholm delivered a technically brilliant race, maintaining his positional advantage over Rai, on the lane inside him, through the first 300 metres.

The American briefly threatened to pull level as they sprung into the final straight but the double world champion pushed again and was a clear winner.

However, having put his name up alongside some of the all-time greats of athletics history, he was still able to somehow suggest there is room for improvement.

"I can't believe the time, it's so fast," he said. "A lot of the time I am asked about the perfect race. I said it didn't exist but this is the closest I've ever come. I didn’t touch one hurdle. I was even able to find another gear coming home, so ‘wow’.

"I had a world championship, European championship, the world record, the European record, but the Olympic gold medal is what everybody talks about. I knew this race was going to be the toughest of my life, but I was ready.

"Now I need to set myself new goals, I don’t think I’m done yet."