Omanyala, who set an African record of 9.77 seconds last year, served a 14 month doping ban four years ago. He failed to make the final at last month’s World Championships after arriving in the United States hours before the heats due to visa problems.
Impressive in the semi-final he looked the favourite on Wednesday and duly controlled the final from gun to tape, flying out of the blocks and surging clear and looking more like a barrelling rugby prop than a sprinter to win in 10.02 seconds.
He is the second Kenyan to take the title after Seraphino Antao in 1962, when the event was still run over 100 yards.
South Africa’s defending champion Akani Simbine took silver in 10.13 with Yupun Abeykoon from Sri Lanka getting the bronze in 10.14.