Bromell set a personal record and is the sixth runner of all time in the distance.
Omanyala is fast and funny eight through the ages after his African record.
It was the fifth time Omanyala broke the Kenyan record.
Bromell won three of the world's four best times this year but had a dip at the Olympics in Tokyo and was eliminated already in the semifinals.
25-year-old Omanyala has gone under the radar and has a remarkable improvement in earnings.
Last year, he ran the distance of 10.32 as the best.
Shortly after the Olympics, where he was eliminated in the semifinals, he went for the first time in ten seconds and had 9.86 as the best time before today's lightning effort in Nairobi.
Old Justin Gatlin, 39, finished third in the race at 10.03.