World champion Noah Lyles and defending champion Marcell Jacobs both qualified for the final of the men's Olympic 100m final on Sunday.
But it was the Jamaican pair of Kishane Thompson and Oblique Seville who looked like they had hit the track at the Stade de France in top form.
Lyles clocked 9.83sec in finishing second behind Seville, who won the first semi in a blistering personal best of 9.81sec.
There was a surprise in the second semi featuring Jacobs as South African Akani Simbine won in 9.87sec ahead of Botswana's Letsile Tebogo (9.91sec).
Jacobs dipped at the line to edge Kenny Bednarek from the United States for third place by a hundredth of a second in a season's best of 9.92sec.
That was just enough to see the Italian and the American qualify for the final as the two fastest finishers outside the two automatic spots from each of the three semis.
Thompson looked impressive as he won the third and final semi-final in 9.80sec ahead of American Fred Kerley in 9.84sec.
The final is scheduled for 21.50 SAST.