RIO DE JANEIRO — Only Usain Bolt could have done this, bringing down a historic lightning strike to steal the thunder that should have belonged to 400-meter runner Wayde van Niekerk’s shiny new world record.

Even when not at his best because of what he called a “really stupid” too-quick turnaround between the 100-meter dash semifinals and the showcase final, Bolt is the most entertaining performer in the track and field universe. Recovering from a slow start, he powered his way past American Justin Gatlin on Sunday night to win in 9.81 seconds and become the first athlete to win three straight Olympic 100-meter titles.

Gatlin, the last man not named Bolt to win the Olympic 100 (at Athens in 2004), crossed the line in 9.89 seconds. Canada’s Andre De Grasse, who won two NCAA titles for USC before turning pro, was third in a personal-best 9.91.

Bolt’s winning time was a season best but still pedestrian for a world-record holder. His accomplishment, though, was sublime. The crowd realized this was a slice of sports immortality, roaring as he took a victory lap and laughing as he paused to take selfies with starstruck fellow athletes, reluctant to leave Olympic Stadium and break the spell he had cast over them yet again.

“I told you guys I wanted to set myself apart,” Bolt told reporters. “It was great. This is what I came here for. It’s the first step in the right direction.”

He overtook Gatlin in the final 15 meters or so, using the long legs of his 6-foot-5 frame to gobble up ground. Fans had designated Gatlin the villain, booing him when he entered the stadium and again when he was introduced, though it wasn’t clear if they acted out of love for Bolt or contempt for Gatlin’s two drug suspensions. Gatlin seemed annoyed but said the jeers didn’t bother him. If he had been the crowd favorite, the outcome likely would not have been different.

“I ran my heart out as much as I could,” Gatlin said. “I was under fatigue going from the semifinals to the final. And I just tried to dial myself in and run as hard as I could.”

De Grasse, lucky enough to run beside Bolt in the semifinal and final, admittedly was caught up in the moment. But he couldn’t catch up to the surging Bolt. “I saw him going and I tried to go with him but he’s got that extra gear,” De Grasse said. “It was a great race and great to be part of history.”

On almost any other night, van Niekerk’s historic 400-meter run of 43.03 seconds would have been the biggest story, but Bolt was Bolt. Still, it’s very much worth appreciating the South African’s feat in adding the Olympic title to his 2015 world championship.

Van Niekerk not only smashed the world record of 43.18 seconds set in 1999 by Michael Johnson, he did it in a field that included 2012 Olympic champion Kirani James of Grenada (second, in 43.76 seconds) and 2008 Olympic champion LaShawn Merritt of the U.S., who was third in 43.85. And he did it from Lane 8, where it’s difficult to judge the positions of other competitors.

“I literally need to go back and watch the race,” said van Niekerk, who credited Bolt with encouraging him while van Niekerk spent two weeks training in Jamaica. “I thought someone was going to catch me.”

Not on Sunday. “I thought the time was going to be fast. I didn’t think it was going to be 43.0 fast, but it is what it is,” said Merritt, who’s also entered in the 200. “You take it, the race is over and you get ready for what’s next.”

There is no more next in these Games for 1,500-meter runner Brenda Martinez of California. She faded to last in her semifinal heat and didn’t advance, though Americans Shannon Rowbury (4 minutes 4.46 seconds) and Jenny Simpson (4:05.07) moved on to Tuesday’s final. Martinez lost a chance at an Olympic berth in the 800 at the U.S. trials when she stumbled and fell out of the top three; the 1,500 was a worthy consolation but she was physically and emotionally spent Sunday.

“I don’t know what happened on that last lap,” she said. “I don’t think I hit the wall. I don’t know why I wasn’t responding. I don’t think it was so much mental as it was maybe my body. I just didn’t have the legs to go like I normally do.”