On Sunday, Commonwealth champion Ferdinand Omanyala finished third in a star-studded field at the Diamond League in Rabat, his first 100m loss of the year.
American Fred Kerley won in 9.94 seconds (MR), with former African record holder Simbine of South Africa coming in second in 9.99 seconds and Omanyala rounding out the podium in 10.05 seconds.
Trayvon Bromell of the United States finished fourth, and Letsile Tebogo of South Africa finished fifth.
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The organizers had assembled one of the strongest 100m lineups in recent memory, including Olympic Champion Marcell Jacobs, who did not race because of a back problem.
Omanyala got off to a fast start but lacked the top-end speed to keep up with world champion Kerley before Simbine raced past him in the final meters.
In the women's 800m, Commonwealth champion Mary Moraa was in another league, following up her decisive victory at the Kip Keino Classic with another excellent win.
The defending Diamond League champion won in 1:58.72, beating Australia's Catriona Bisset and American Sage Hurta-Klecker in third.
Emmanuel Wanyonyi, the former world junior champion, continued his good form over 800m with a clear victory in Morocco's capital.
The teenager outpaced an experienced field to win 1:44.36, ahead of Commonwealth Games winner Wycliffe Kinyamal, who finished second.
Olympic and world champion Emmanuel Korir came in ninth place.
Kenya's problems in the men's 3000m steeplechase continued, with Morocco's Soufiane El Bakkali dominating at home at night's last event.
The Olympic champion ran a lifetime best of 7:56.68 to finish well clear of Ethiopian Getnet Wale (8:05.15) and Kenya's Abraham Kibiwot (8:05.51).
