TOKYO -- When Sydney McLaughlin-Levrone powered though the final curve of the 400-meter final at world championships, she glanced to her right and saw something that hadn't been there in a while.

The best way to explain how McLaughlin-Levrone became the first woman in nearly 40 years to crack the all-but-unscalable 48-second mark in the 400 is that the opponent she beat Thursday night on a rain-glistened track in Tokyo, Marileidy Paulino, broke 48 seconds, too.

"You don't run something like that without amazing women pushing you to it," McLaughlin-Levrone said.

The final numbers in this one: McLaughlin-Levrone 47.78 seconds. Paulino 47.98.

They are the second and third fastest times in history, short only of the 47.60 by East Germany's Marita Koch, set Oct. 6, 1985 -- one of the last vestiges from an Eastern Bloc doping system that was exposed years after it ended, but too late for the records to be stripped from the books.

McLaughlin-Levrone, who stepped away from hurdles to see what she might be able to do in the 400 flat, said she was every bit as focused on winning the title in a new event as going after a record that had always been thought unapproachable.

And Paulino, the reigning Olympic and world champion in this event, wasn't just going to give it away.

This was an even race, the likes of which McLaughlin-Levrone hadn't been part of in at least three years in the hurdles, as the runners rounded the stretch. McLaughlin-Levrone opened a gap of about four body lengths with 30 meters left, but Paulino was actually gaining ground when they both lunged into the finish line.

"At the end of the day, this wasn't my title to hold onto, it was mine to gain," McLaughlin-Levrone said. "Bobby uses boxing terms all the time. He said, 'You've got to go out there and take the belt. It's not yours. You've got to go earn it.'"

Bobby is Bobby Kersee, the wizardly coach who helped transform McLaughlin-Levrone into the greatest female hurdler ever and might be doing the same in the 400. Brutal training sessions with one-time UCLA quarter-miler Willington Wright were part of the regimen.

"I felt that somebody was going to have to run 47-something to win this," Kersee told The Associated Press. "She trained for it. She took on the challenge, took on the risk. She's just an amazing athlete that I can have no complaints about."

As the times came up on the scoreboard, the crowd roared. The enormity of the moment wasn't lost on anyone.

Nobody had come within a half-second of Koch's mark until this race. Third-place finisher Salwa Eid Nasar clocked 48.19, a time that would have won the last two world championships.

"It's just amazing what the 400 has become the last couple years," said Britain's Amber Anning, who finished fifth in 49.36. "I love it, it makes me want to step up my game. To see it done, it gives hope to us that anything's possible in the 4."

Paulino, meanwhile, was more focused on her unique place in history than not winning the race.

"I'm thankful for having the opportunity to break 48," she said. "I still feel like a winner. I've spent five years every day training for this."

McLaughlin-Levrone took up the 400 flat in 2023, but injuries derailed her run at a world championship that year. She focused on hurdles last year for her second Olympic gold medal in the event, then came back to the flat for 2025.

When she ran 48.29 in the semifinal, she broke a 19-year-old American record and said she still felt she had "something left in the tank."

Then, with a push from Paulino, she let it loose.

"Today was a really great race for track and field, and I'm grateful to put myself in position to bring an exciting event to our sport," McLaughlin-Levrone said.

It's still an open question as to whether she will stick around in this race long enough to go after Koch's record, or return to the hurdles, where the number "50" hangs out there much like "48" did in the race she won Thursday night.

Nobody had thought much about 50 seconds in hurdles until McLaughlin-Levrone started breaking the record in that event on a semi-regular basis. Four years ago at the Olympics, she lowered it to 51.46 in the empty stadium in Tokyo.

She broke it three more times and then, in Paris last year, took it down by another .28 seconds to 50.37.

Over time, those races became mere matters of McLaughlin-Levrone against the clock.

This time, something different -- a bona fide showdown for the gold medal that knocked down a once-unthinkable barrier in racing.

Whatever McLaughlin-Levrone's next move is, it's bound to be fast.

"I think, now, 47 tells her that she can break 50," Kersee said. "Knowing her, she's probably going back to the hurdles and try to take what she learned now in the quarter(-mile) and try to execute a plan to run 49.99 or better."

Sydney McLaughlin-Levrone explains how she delivered historic 400 time at worlds meet