WATCH: Bolt's reaction to Wayde's WR is priceless

Cape Town - South Africa's Wayde van Niekerk left Jamaican sprint star Usain Bolt stunned after winning the Olympic 400m gold medal in record breaking time.

Van Niekerk smashed American Michael Johnson's 17-year old record by 0.15, winning in 43.03.

Some 25 minutes later, Bolt won the 100m title in 9.81.

But Bolt was left stunned when he saw Van Niekerk break the world record.

Watch the video below:

Usain Bolt's reaction to Wayde van Niekerk's WR 43.03 in the 400m final. #Rio2016 pic.twitter.com/GJIaMLGzIZ

— Stephen Nelson (@Stephen__Nelson) August 15, 2016

Bolt also went over to congratulate Van Niekerk in person.

It was a fitting moment between two champions, and Van Niekerk revealed the nature of their conversation afterwards.

"I was over there (Jamaica) for about two weeks training with him," Van Niekerk said.

"He’s been such a huge rock in inspiring me as an athlete.

"He told me back in Jamaica that I would break the world record and he came to me afterwards and said ‘I told you that you can do it’.

"These are guys that inspire me each and every day to be the best Wayde that I can be."

Van Niekerk added that he would love the opportunity to race against Bolt one day.

"My favourite event is the 200m so I would love to race him one day when I’m big," the fastest man ever over 400m said.