Usain Bolt was all smiles as he advanced to the 200m final with the fastest time of the year and is now one win from his eighth Olympic gold.
Bolt ran 19.78 seconds in the second of two semifinal heats.
He was pushed all the way by Canada's Andre de Grasse in the lane beside him.
In a game of cat and mouse, Bolt let De Grasse remain on his shoulder right up to the line.
But as they were laughing at each other, Bolt pushed his chest just across the line for 19.78 while De Grasse set a Canadian record of 19.80.
The pair shared a smiling conversation beyond the finish line, but Bolt sensationally declared in his round of interviews immediately after the race that he was put-off by De Grasse's late charge when he believes it was "unnecessary".
"I said, 'What are you doing, it's a semi-final.'
"I think he wanted to push me. I was a bit lazy but I got round."
Bolt told Channel 7 he told De Grasse in no uncertain terms that the Canadian was out of line.
"It was not needed," Bolt said.
"De Grasse just did that unnecessarily. It wasn't cool, but it's just one of those things.
"I was asking him, 'What is he doing?'
"He said, 'I have to put on some pressure,' and I was like, 'Why? It's the semi-finals, you know what I mean.'
"It's just one of those things. He's young."
De Grasse said he simply wanted to test Bolt.
"We were just having fun," he said.
"I just wanted to go out there and push him to his limits a bit.
"I had to push him a little bit and see what he had left in the tank."
Images of the pair running side-by-side over the finish line with smiles all over their face was reported around the world as a moment the couple took their "bromance" to the next level.
The pair have been racing together for years and are both Puma-sponsored athletes.
It didn't stop Bolt putting De Grasse in his place.
Bolt earns an automatic place in tomorrow's final. De Grasse will also advance.
After winning the 100 metres to clinch his third consecutive Olympic title in that event, Bolt set his sights on a third straight sprint double and added another challenge: He wants to lower his world record in the process.
Bolt set the world record of 19.19 at the 2009 world championships in Berlin. He set the Olympic record in Beijing in 2008.