Michael Phelps added a 19th gold medal to his ever-growing record haul Sunday night.
Phelps surged ahead with a 47.12-second split in the second leg of the 4x100-meter freestyle relay to give the U.S. team a lead it held for good.
"When I was on the block, I honestly thought my heart might explode out of my chest," Phelps said. "I was so hyped tonight and so excited."
Swimming in his fifth Olympics, Phelps has repeatedly said he's in love with his sport again. And on this night, that love translated to speed that would have made his younger self proud.
It was Phelps' first race of these Rio 2016 Olympics, and the 31-year-old looked like the version of himself who had dominated Olympics past.
"Tried to give these guys as much open water as I could," Phelps said as he was interviewed immediately after the race on NBC.
He succeeded in that regard, and earned his 23rd career Olympic medal.
The U.S. finished in 3:09:92, ahead of France (3:10.53) and Australia (3:11.37).
It was France that won in 2012, beating the Americans, and Phelps sought to avenge that not-so-satisfying second-place finish.
"We wanted to bring that relay back to American soil," he said. "We had some sour tastes in our mouth, for me, in 2012, and I'm glad it's back on our soil."
Bob Bowman, Phelps' personal coach and also the coach of the U.S. men's team in Rio, put Phelps on the second leg, with Caeleb Dressel leading off, Ryan Held swimming the third leg and Nathan Adrian anchoring.
Phelps, after a spectaular turn, took the lead. Held and Adrian kept it.
"A week ago, we had a time trial where he proved he belonged there," Adrian said of Phelps' not-always-certain spot on the relay team. "He obviously proved he definitely belonged there tonight."
Phelps will begin his individual schedule Monday with a preliminary heat and evening semifinal in the 200-meter butterfly.
But relays have long been important to his story.
He built the entire first half of his career toward Beijing in 2008, where he planned to break Mark Spitz's record of seven gold medals at one Olympics.
But for Phelps to pull it off, the Americans needed to win the 4x100 freestyle relay against ferocious competition from the French and the Australians.
Phelps set an American record for the 100 freestyle on the opening leg, but the U.S. lost its lead on the third leg, and anchor Jason Lezak was a body length behind Alain Bernard of France as they turned for the final 50 meters.
Over that span, Lezak pulled off perhaps the greatest rally in Olympic history and touched the wall just ahead of Bernard.
Phelps unleashed a wild bellow, clenching both fists in exultation. It's still a strong candidate for the most dramatic race of his career.
He ultimately eclipsed Spitz when the Americans won gold in the 4x100 medley relay, an event they've always dominated.
But in recent years, American relay teams have faltered, at least relative to their former dominance. For example, the U.S. men didn't even qualify for the final in the 4x100 freestyle at world championships last year.
Phelps has not hidden his distress at this state of affairs.
He did not swim the 100-meter freestyle at Olympic Trials to establish a time that would clearly put him on the relay team here. But he gave hints he'd like to participate.
"Just being able to be on a team like that is something that is very special that I've always enjoyed," he said at trials.
Bowman said Phelps' swim Sunday, which featured a supernaturally great turn, was a good omen for the week ahead.
"Usually when one thing is pretty good with him, everything is really good," he said.