Reigning world champion Fred Kerley won the 100 metres at the Diamond League meeting in Rabat on Sunday in 9.94 seconds in the absence of Olympic champion Marcell Jacobs.
South Africa's Akani Simbine finished second behind Kerley in 9.99sec with Kenyan sprinter Ferdinand Omanyala third (10.05).
Trayvon Bromell, a world bronze medallist last year in Oregon, could only manage fifth in a time of 10.10sec.
"I can't describe my happiness for winning this race and hitting the meeting record today," said Kerley.
"This is the result I was expecting and I will keep up to achieve and reach the world championship in the best shape ever."
Fred Kerley pips Akani Simbine and Ferdinand Omayala to first place in the Men's 100m race ?????#DiamondLeague pic.twitter.com/4kuzdrmGr7
— SuperSport ?? (@SuperSportTV) May 28, 2023
Jacobs, who beat Kerley to gold at the 2020 Olympics, pulled out of their much-anticipated showdown earlier in the week due to a back nerve problem.
The pair have not faced each other since Tokyo but could meet on June 2 in the next Diamond League event in Florence.
Kerley will defend his 100m crown at the world championships in Budapest in August and could target the 200m as well.
Jamaican world champion Shericka Jackson won the women's 200m in 21.98sec, while Morocco's Soufiane El Bakkali delighted the home crowd by running away from the field in the 3000m steeplechase.
The Olympic and world gold medallist set a personal best of 7:56.68.
Commonwealth Games champion Rasheed Broadbell of Jamaica edged two-time world champion Grant Holloway in the 110m hurdles, winning in 13.08sec.