Steven Gardiner of the Bahamas wins the 400 meters.

TOKYO — Steven Gardiner of the Bahamas emerged from a crowded pack to win the gold in the men’s 400 meters. Gardiner, who finished in 43.85 seconds, was challenged by Anthony Jose Zambrano of Colombia, who finished second, and Kirani James of Grenada in third. It was James’s third straight Olympic medal in the event: He won the gold in 2012 and the silver in 2016. Grenada has three Olympic medals in the country’s history, and they all belong to James.

Michael Norman, the U.S. champion, finished fifth, one spot behind his American teammate, Michael Cherry.

And sometimes, those records are falling earlier than expected — in qualifying heats.

Ask Matthew Centrowitz, who had been attempting to defend his Olympic title in the men’s 1,500 meters. He ran his fastest time of the year on Thursday in his semifinal heat — and fell short of advancing to Saturday’s final. His time of 3:33.69 was good enough for ninth, well behind Abel Kipsang of Kenya, who set an Olympic record (3:31.65) and won the heat.

Cole Hocker, the 20-year-old American who won the event at the U.S. trials and only recently completed his sophomore season at the University of Oregon, was more fortunate. He merely had to run a lifetime best of 3:33.87 to finish second in his heat and secure one of five automatic spots in the final.

Centrowitz, 31, said he was disappointed with his tactics.

“We all knew it was going to be a fast race, and I just put too much emphasis on being right off the shoulder of whoever was in the lead,” he said. “When they’re running the Olympic record in the heats, you can’t be out in Lane 2, Lane 3 and wasting energy like that.”

Asked about possibly competing through another Olympic cycle, Centrowitz said: “It’s hard to say. We’ll have to finish the season up and see how it goes. Obviously, at some point, age catches up to us.”

Women’s Pole Vault

Katie Nageotte of the U.S. made sure her first Olympic experience was a memorable one. She cleared 16 feet three-quarters of an inch to win the gold. Anzhelika Sidorova of Russia finished second, and Holly Bradshaw of Britain was third.

The Decathlon and the Heptathlon

The multi-events crowned their champions. Damian Warner was the Olympic gold medalist in the decathlon, setting Canadian and Olympic records with 9,018 points. Kevin Mayer of France won the silver, and Ashley Moloney won the bronze. Garrett Scantling of the U.S. was fourth.

And Nafissatou Thiam of Belgium became the first woman to repeat as the Olympic heptathlon champion since Jackie Joyner Kersee won consecutive titles for the U.S. in 1988 and 1992. Thiam was joined on the medal podium by a pair of Dutch athletes: Anouk Vetter in second and Emma Oosterwegel in third.