Norway's Karsten Warholm smashed the world record in the men's Olympic 400 metres hurdles final, breaking the 46-second barrier on the way to gold medal glory.

Warholm finished in 45.94 seconds, well ahead of his own previous record mark of 46.70. USA's Rai Benjamin claimed silver in 46.17, also beating the old world record, with Alison dos Santos taking bronze in 46.72.

"It's by far the biggest moment of my life," Warholm said. "It defines everything, all the hours I put in, everything that my coach has been working for.

"With all the respect for all the athletes, there are athletes that were not good that will get an Olympic gold. Rai running 46.17 would deserve a gold medal. It is crazy, it is just an honour to be a part of it. I never thought in my wildest imagination that this would be possible."

Asked about his dash to the line in the closing metres, Warholm added: "I couldn't even feel my legs. I knew I had a crazy American trying to catch me, so I ran for my life."

Germany's Malaika Mihambo admitted she could not watch the finale to the women's long jump as she won gold.

Mihambo took the lead with a jump of 7.00m with her final attempt before USA's Brittney Reese and Nigeria's Ese Brume had their last jumps.

Neither could better the leading mark, with Reese settling for silver with 6.97 metres on countback ahead of Brume.

"It was really hard to watch, so I tried to just have a sneak peek on the display and see how far it was," Mihambo said.

"I really don't like this position where you cannot do anything about it, and you just have to let the girls do what they're able to do. You have to wait, so it was a horrible moment, but at least it was short.

“I feel overwhelmed. It was, I think, the most exciting women’s long jump competition in history."

DURANT DOMINATES AS USA SURVIVE SCARE

The United States did not have it all their way but triumphed 95-81 over Spain to seal a spot in the men's basketball semi-finals.

Spain led by as much as 10 points in the second quarter before USA drew level by half-time and accelerated in the second half. Spain again closed within four points of the gold medal favourites in the final quarter, inspired by Ricky Rubio's 38 points.

Kevin Durant excelled for Team USA, with 29 points and four assists, while Jrue Holiday contributed 12 points and five assists as they capitalised on a 17-9 turnover differential.

USA lost to Australia and Nigeria in exhibition games prior to Tokyo 2020 before losing their Olympics opener to France but have since steadied.

The winner of Australia-Argentina will play USA in the semi-finals on Thursday.

NBA duo Zoran Dragic (27 points, six rebounds and four assists) and Luka Doncic (20 points, eight rebounds and 11 assists) starred as Slovenia also progressed to the semi-finals with a 94-70 win over Germany.

CARRINGTON'S GOLD KAYAKING DOUBLE

New Zealand's Lisa Carrington had a golden day in the kayaking, remarkably winning two gold medals within an hour.

Carrington won her third straight gold in the women's kayak single 200m with an Olympic best time of 38.12 seconds, ahead of Spain's Teresa Portela and Denmark's Emma Jorgensen.

The New Zealander backed up alongside Caitlin Regal to win the women's kayak double 500m final with a world best time of 1:35.785.

Carrington joined fellow kayakers Ian Ferguson and Paul MacDonald and equestrian great Sir Mark Todd as the only New Zealanders to have won five medals at the Olympic Games.

The 32-year-old may win more medals too, competing in the K1 500 event which starts on Wednesday.

“Today was about taking just one race at a time," Carrington said. "There's a plan, and it was just about executing it. For me, it was just trying to stay in the moment and doing the best I can. We've worked really hard and knew today was going to be a big day.”

HENDRICKX POWERS BELGIUM INTO HOCKEY FINAL

World champions Belgium qualified for the gold medal match of the men's hockey after a commanding final quarter sealed a 5-2 win over India.

Belgium piled on three fourth-quarter goals to guarantee a medal in the decider where they will face either Australia or Germany.

Alexander Hendrickx scored a hat-trick including two of the Red Lions' goals in the final quarter after India had fought back from an early deficit to lead 2-1 at quarter-time.

Drag flick expert Hendrickx has scored an unrivalled 14 goals during Belgium's Tokyo 2020 campaign, eight clear of the next best, Australia's Blake Govers.

Hendrickx said: "It's really a team job that comes together. It's my name on the scoresheet, but it's a team job."

World number one Australia and sixth-ranked Germany meet later on Tuesday to determine the other gold medal match finalist.