Rio de Janeiro - Wayde van Niekerk was stunned when he crossed the line in a new 400m world record time to clinch the Olympic gold medal.
Van Niekerk installed himself as the new fastest man ever over the one-lap sprint in a time of 43.03 seconds.
He smashed American track legend Michael Johnson’s mark set at the 1999 world championships by 0.15s.
"I still think you need to let it sink it , it is still so fresh I don't think I was in that race tonight," Van Niekerk said.
"That is how unreal it feels, I even had the opportunity to take a victory lap so it is a lot of improvement."
Defending champion Kirani James of Grenada finished in 43.76 with LaShawn Merritt of the United States finishing third in 43.85s.
"I was really amazed by the time and I went in with no expectations, I went out there for any medal tonight," Van Niekerk said.
"I said God, I just want to be top three tonight and looked what happened.
"I got top three, I got a world record, I got a lifetime best.
"Things have been such a blessing for me tonight."
James said Van Niekerk demonstrated the 400m sprint was moving into a new era.
"If you look at the silver and bronze medallists from 2012 weren't in the final," James said.
"It just shows how much the event is evolving and how much guys are improving, so we really can't take anybody for granted.
"On any given date, we saw today, anyone can win and today the world record. It's just incredible."
Independent Media