LOS ANGELES • American Trayvon Bromell won the 100 metres and reigning Olympic champion Shaunae Miller-Uibo of the Bahamas won the 400m in feature races at the Oregon Relays on Saturday.

The meet, staged in breezy and wet weather, was the first elite event contested at the University of Oregon's renovated Hayward Field, site of the United States Olympic trials in June and next year's World Championships.

Bromell jumped ahead at the start and led all the way to win in 10.01 seconds, with fast-closing world 200m champion Noah Lyles second in 10.17 and Liberia's Emmanuel Matadi third in 10.19.

"I started good, just tried to block out the weather and stay focused on the race," Bromell said. "I was just happy."

Lyles said the event was a first step on the path to the Tokyo Olympics.

"Today's races are all about the stepping stones to get into the Olympics. I want to get my spikes in the track so when I come back, it won't be unfamiliar to me."

Miller-Uibo took the 400m in 49.08, this year's world-best time.

"Wanted to get a good run in to see where I'm at. I think I'm in a good place," she said.

"It's a blessing to come in here and run a really fast time. I'm really happy with it."

She is married to Estonian decathlete Maicel Uibo, a 2019 World Championships runner-up who also seeks a Tokyo title.

"The dream is to come back with gold medals, both of us," Miller-Uibo said.

Nigeria's Blessing Okagbare won the women's 100m in 10.97, the second-best time in the world this year.

Allyson Felix, a six-gold Olympic champion and 13-gold world champion, was seventh in 11.30 as she aims for a 200m Olympic berth at the age of 35.

American Chase Ealey won the women's shot put with a heave of 18.93m with Jamaica's Danniel Thomas-Dodd second on 18.46. Reigning Olympic champion Michelle Carter of the United States was ninth on 16.94.

Two-time British Olympian Eilish McColgan won the women's 5,000m in 14min 52.44sec while American Isaac Updike won the men's 3,000m steeplechase in a personal best of 8:17.74, the fastest time in the world this year.

Reigning world champion Anderson Peters of Grenada won the javelin with an effort of 82.72m while American Rudy Winkler won the men's hammer in a world-best 81.98m this year.

In Des Moines, Iowa, Britain's Cindy Sember won a world-class women's 100m hurdles showdown at the Drake Relays while four-time defending champion and world record-holder Kendra Harrison fell at the second hurdle. She did not finish but rose and walked off apparently uninjured.

Sember, who has battled back from a ruptured Achilles tendon, surged late to win in 12.57 with American Christina Clemons second in 12.59 and Britain's Tiffany Porter third in 12.80.

"The journey has been a long road, but I'm very blessed to get back to where I knew I could be," Sember said.

American Dawn Harper-Nelson, the 2008 Olympic champion and 2012 runner-up attempting a 100m hurdles comeback at 36 after having a baby, was seventh on 13.28 in her debut this year.

"I'm here to prove it's possible to be a mother and be out here," she said. "I'm not too pleased with the time but I'm happy to be out here."

About 2,800 spectators - about 20 per cent of Drake Stadium capacity - were allowed to attend under Covid-19 safety protocols.

Reigning Olympic champion Ryan Crouser won the shot put with a heave of 21.93m, the best in the world this year. He has not lost since finishing second at the 2019 World Championships.

Two-time world pole vault champion Sam Kendricks, who took bronze at the 2016 Rio Olympics, won by clearing a 2021 world-best height of 5.86m on his final attempt.

AGENCE FRANCE-PRESSE