Christian Coleman showed again he is the man to beat in the 100 metres as he cruised to victory at the US Nationals and World Championship trials with another sub-10 second run on Friday.
World silver medallist Coleman, who holds the year's fastest time of 9.81 seconds, won the final in 9.99 seconds after clocking 9.96 in the semi-finals.
"It felt pretty smooth," said Coleman after running into a slight headwind.
"I wish they had turned the race around so we could have a tailwind, but even then it felt good."
Asked if he was the man to beat in Doha, the 23-year-old said: "I feel very comfortable with that."
He will start in the 200m on Saturday in his bid for a sprint double.
Mike Rodgers and Christopher Belcher joined him on the U.S. team for Doha. Both were timed at 10.12 seconds but Rodgers was runner-up by six thousandths of a second.
Justin Gatlin, who has automatic entry to Doha as the reigning 100m champion, did not run the final after finishing third in his semi-final in 10.16 seconds.
Teahna Daniels, who turned professional this week, won the women's 100 in 11.20 seconds with a strong last half. The 22-year-old Texan had finished fourth in the U.S. collegiate championships.
"It's surreal. I can't put into words how I felt at that moment," Daniels said. "It means so, so, so, so much."
Olympian English Gardner clocked 11.25 for second and Morolake Akinosun took third in 11.28.
Sha'Carri Richardson, who won the collegiate race in a world under-20 record 10.75 seconds, surprised by finishing last in 11.72.
Allyson Felix, a six-times Olympic gold medallist, continued her bid to race at the worlds, the new mum making the final of the women's 400 metres with a run of 51.45 seconds that earned third place in her semi-final, the fifth fastest of the eight finalists.
The 33-year-old is racing for the first time in 13 months after giving birth to a daughter in November and needed to qualify on time on Thursday to make the semi-final.
"It is such a different mindset this time around," the 11-time world champion said. "I don't think I could say before it feels good to be in a final.
"But I have to keep reminding myself what I have been through this year and just be grateful and take it one day at a time."
Shakima Wimbley had the fastest qualifying time of 50.20 seconds.
The year-best Michael Norman paced men's qualifying, claiming his semi-final in 44.04 seconds as he edged Fred Kerley by five-hundreds of a second.
Paralympian Blake Leeper ran a personal best of 44.38 seconds while running on blades, the third best time of the day.
The IAAF has not recognised any of his times this year, however, and it has not been decided whether he can run in Doha, Leeper said.
Brown upsets De Grasse in Canadian 100 metres
Aaron Brown edged Olympic triple medallist Andre De Grasse in a photo finish to win the 100 metres at the Canadian championships/world trials in Montreal on Friday.
Brown, a bronze medallist on Canada's Olympic 4x100 metres relay team, claimed his second 100 metres title in 10.021 seconds.
De Grasse, the Olympic 100 metres bronze medallist, was second in 10.024 as they qualified for September's world championships in Doha.
Both had run sub-10 seconds in the semi-finals, the 27-year-old Brown clocking a personal best 9.96 seconds and De Grasse later running 9.98 in his semi-final.