Sydney McLaughlin-Levrone lowered her world record once again, running the 400m hurdles in 50.65 seconds on Monday morning AEST to win the US Olympic trials.

In only her fourth long hurdles race of the season, the 24-year-old defending Olympic champion cleared all 10 barriers with ease, then went on a dead sprint to the line to break the record for the fifth time. Four of those marks have now come on track at University of Oregon's Hayward Field.

She held her hand over her mouth and stared in amazement when she saw the time come up. The mark was .03 seconds better than her run at Hayward in the 2022 world championships.

"My husband asked me yesterday, 'What do you think you can do?' and I told him "I don't know,'" McLaughlin-Levrone said in an interview over the stadium PA system. "Then today, I crossed the line and I'm like, 'Oh, snap.' I'm blessed and happy to be here."

In an event that used to be decided by steps or slivers, McLaughlin-Levrone's victory was by 1.99 seconds over Anna Cockrell and 2.12 over Jasmine Jones.

It doesn't so much reset the storyline for the Olympics — McLaughlin-Levrone would've been the big-time favourite either way — as it makes track rethink what's possible.

From 2003-19, the world record in this event stayed stuck at 52.34. American Dalilah Muhammad broke it twice in 2019 — the second time at world championships in a race that demoralised McLaughlin-Levrone and sparked a move over to coach Bobby Kersee.

Kersee changed everything for her. One of the biggest adjustments was dropping her to 14 strides between the early hurdles. It was a game-changer that has put her in a class by herself since she first set the record in 2021 — on the final day of trials on the track in Eugene, just like this time.

"I've been growing as a person and growing as an athlete" with Kersee in charge, McLaughlin-Levrone said. "He challenges me and pushes me in ways I didn't think were possible."

Now, instead of a much-anticipated showdown with Femke Bol of the Netherlands, the conversation might turn to when the 50-second mark might come tumbling down in this race. Maybe as soon as August 8, which is the date of the Olympic final in Paris.

"It could happen," hurdling great Edwin Moses told The Associated Press. "She might need a couple more races, but that's about it."

AP