McLaughlin-Levrone, the world record holder in the 400 hurdles, last competed in the event in August 2022.

The American displayed no signs of rust at the Edwin Moses Classic in Atlanta, as she effortlessly surged past her competitors to better Jamaican Rushell Clayton's previous season-leading mark of 53.72 by over a second.

"It's a progression, you know. Shaking the rust off after two years - I'll take a 52.7," McLaughlin-Levrone said after the race.

"There are things to work on and I haven't had much hurdle practice, so there's things to improve."

McLaughlin-Levrone, who missed last year's World Championships due to a knee injury, has been competing entirely in the United States in the build-up to this month's U.S. Olympic Team Trials.

"I love racing and I love Europe, but I think in a year like this and coming back from injury last year I just wanted to be safe," McLaughlin-Levrone said.

"Travel can take a lot out of the body, and hopefully I can get some more races, but I'm just playing it safe until I get to trials."