Former world champion Justin Gatlin has failed to qualify for the men's 200m final at the Olympic Games.
The controversial American needed a top-two finish in the third heat or a faster time than 20.08s but after fading and looking across to his right in the closing stages, he could only claim third in a time of 20.13s.
There were no such problems for defending champion Usain Bolt, who eased through the first race in a time of 19.79s, while Great Britain's Adam Gemili also made Thursday's final.
The 22-year-old finished in third in the opening semi-final but he was able to hold on to progress as a fastest loser.
Danny Talbot and Nethaneel Mitchell-Blake both recorded times of 20.25s but it was not good enough to make the final.