To put Warholm's run into perspective, only four runners in history have ever clocked sub-47sec times, let alone sub-46.
The race also included seven of the eight runners recording personal best times.
Touted as one of the stand-out events of the 10-day track and field programme at the Olympic Stadium, the cream of a very good hurdling crop did not fail to deliver in a thrilling race in stifling midday heat and humidity.
It was a race that had everything and came down to the final 20m.
Eyes bulging at the world record time flashed up on the big screen, Warholm roared and spontaneously ripped open his shirt amid gasps from sparse pockets of fellow athletes and team officials at the Olympic Stadium.
Karsten Warholm, of Norway celebrates as he wins the gold medal in the final of the men's 400m hurdles. Photo / AP
Karsten Warholm, of Norway celebrates as he wins the gold medal in the final of the men's 400m hurdles. Photo / AP
Karsten Warholm, of Norway, reacts after winning the men's 400m hurdles final. Photo / AP
Commentators, including Aussie icon Bruce McAvaney, described it as one of the most iconic performances ever seen at the Olympics – competing with Usain Bolt's 9.63sec 100m run at the London Olympics.
"It will go down as the greatest 400m hurdles ever run and arguably the greatest race we have seen at an Olympic Games. What a contest," McAvaney said.
Former Aussie athletics star Tamsyn Manou said she couldn't speak after the shock of the race.
"I'm in shock. Bruce, I'm in shock. I cannot believe for the men's 400m hurdles there is a 45 second run," she said.
"We've taken this event to a place where I don't think anybody (expected).
"Everybody was talking about a world record, but I don't think anybody would have said it will be won in sub-46 seconds."
American sports commentator Tom Harrington said: "That 400 meters hurdles was the greatest in history".
The world was simply blown away.
Ppl, I don’t think you realize what you just watched. A man just ran Sub 46 in the 400M Hurdles. That’s Beamon’s jump in Mexico City, Bolt’s sub 9.6 in 100 meters. I saw Kevin Young run 46.78 in Barcelona, still can’t believe Warholm ran that fast. Geeeeezzz
