TOKYO >> Sydney McLaughlin broke the world record. Dalilah Muhammad broke it, too.

Only one of of the world’s best hurdlers could win the Olympic gold medal — and McLaughlin came out ahead in the latest installment of the best rivalry in track.

The 21-year-old out of East Orange, New Jersey won the 400-meter hurdles title Wednesday, finishing in 51.46 seconds in yet another history making day on the Olympic oval.

McLaughlin came from behind after the last hurdle to top the defending Olympic champion. Muhammad’s time of of 51.58 also beat McLaughlin’s old record of 51.9, set at Olympic trials in June. But Muhammad got the silver.

For McLaughlin, it was a muted celebration — in part, certainly, because traversing 400 meters while clearing 10 hurdles at 17 miles-per-hour is so much more exhausting than she makes it look.

She sat on the ground, gave a serious look toward the scoreboard — yep, it’s a record … again — then got up and moved toward the hand-sanitizing station. Muhammad came over and gave her a congratulatory hug. They’ll meet again. World championships are next July.

Impressive as McLaughlin’s race was, this record didn’t really surprise anyone.

McLaughlin and Muhammad, a New York City native who went to Southern Cal, have been trading the record, and the wins, for two years. Muhammad first broke the mark at U.S. Nationals in Des Moines, Iowa, in 2019, then lowered it again. to 52.16, at the world championships in Doha.

McLaughlin broke that record earlier this summer at Olympic trials, running her 51.90 to become the first woman to crack 52 seconds.

It felt inevitable that the mark would go down again on a fast track in perfect, hot-and-humid running conditions in Tokyo.

Only a day earlier, Norway’s Karsten Warholm crushed his old world record, finishing the men’s race in 45.94, and runner-up Rai Benjamin’s 46.17 also beat the old mark. Six runners in that race set national, continental or world records.

It was a lot to live up to for the women, whose race was even more eagerly anticipated. They exceeded expectations.

Starting from Lane 7, Muhammad came out of the blocks and made up the lag quickly — too quickly? — as they cruised down the backstretch.

Slowly, steadily, McLaughlin drew even, and they were at nearly a draw when they reached the final 100 meters. As McLaughlin and Muhammad scaled the last hurdle, it was McLaughlin who started inching away.

The .12-second margin was close — but not as close as in Doha, when McLaughlin lost by .07 in a race that changed her thinking.

She had burst onto the scene in 2016, a 16-year-old who loved to tell the story about how she could juggle, and ride a unicycle, and do both at the same time. She could hurdle, too, and had youth titles and trips to major world competitions under her belt on her way to the big-time.

She earned a spot on the U.S. Olympic team in one of the most stacked events on the program, Muhammad, already in her prime, won a gold medal in Rio de Janeiro. McLaughlin was out in the semifinal round. A great learning experience.

“Early on, you could tell right away she was super special and just continued to get better and better every single year,” said Mike McCabe, McLaughlin’s high school coach. McCabe watched the race with a crowd of fans and friends at McLaughlin’s old high school.

By 2019, though, McLaughlin had graduated from high school and had bigger dreams. The races in Des Moines, then Doha, showed how good McLaughlin really was, but left her with an undisputable reality. Muhammad was better.

McLaughlin changed coaches, moving over to work with the famed Bobby Kersee, whose expertise has helped produce what could be its own wing of a track and field Hall of Fame: Jackie Joyner-Kersee, Florence Griffith Joyner, Allyson Felix.

Now, McLaughlin.

Part of Kersee’s magic involved having McLaughlin work at shorter distances, jump off the opposite foot, run indoors more and just get used to different situations. He worked on the mental part, too, and it really is hard to knock her off her stride.

She didn’t get rattled at trials, even when a faulty starting system forced the field back into the blocks three times during a scorching-hot day of qualifying.

Nothing seemed to bother her in Tokyo, where she dealt with quarantine rules, early wake-up times (4 a.m. for the first round) and a drenching rainstorm that hit during the semifinals

“Bobby always talks about Muhammad Ali, and always having to be ready for that left hook,” McLaughlin said earlier this summer when asked how she deals with the unexpected.

In this case, it was another Muhammad — Dalilah Muhammad — who stood in the way of McLaughlin’s goal. She handled that, too, though it’s hard to think this is the end of this rivalry.