Usain Bolt of Jamaica and Andre De Grasse of Canada were ahead of the pack in the 200m semi-finals on Wednesday night.
The first semi-final saw 400m bronze medalist LaShawn Merritt of the United States finish first with a time of 19.94s, with Christophe Lemaitre of France following him through to the final with a time of 20.01s.
The big guns came out for the second semi-final in which Bolt cruised past the finish line in 19.78s, followed closely by 100m bronze medalist De Grasse on 19.80s.
The Jamaican was laughing as he crossed the line just two hundredths of a second clear of de Grasse.
“Andre was supposed to slow down. He didn’t!” Bolt said after the race. “I said: ‘What are you doing it is the semis?’ He said he had to push me.
“I was a bit lazy, I don’t know why, but I executed it.”
There was drama in the final few metres of the third semi-final, as Justin Gatlin of the United States and Yohan Blake of Jamaica were pipped to the finish line by Alonso Edward of Panama and Churandy Martina of the Netherlands, with times of 20.07s and 20.10s respectively.
The veteran American will miss out on the final as his time of 20.13s was not enough; while Blake, who won silver in this event in 2012, also failed to qualify as he finished sixth in the heat with a time of 20.37s.
The two fastest losers to complete the list of finalists are Adam Gemili of Great Britain and Ramil Guliyev of Turkey, with times of 20.09s and 20.10s respectively.