It was billed as the “Race of the Century.”

It turned out to be a race for second, with Australia’s Ariarne Titmus dominating a field that included the last three world record-holders to win the women’s 400-meter freestyle in 3 minutes 57.49 seconds on the opening night of swimming at the Paris Olympics on Saturday.

Canadian teenager Summer McIntosh was second in 3:58.37 followed by American Katie Ledecky, who was only briefly in contention before finishing third in 4:00.86.

Yet if the race was won by Titmus, the buildup came courtesy of Ledecky, who entered Paris’ sprawling La Defense Arena to massive cheers and left it just before midnight after an emotional news conference.

“I love this sport so much I get emotional about it,” she said while fighting back tears. “That’s what carries me through, keeps me going. My tears come out every now and then.”

At 27, this is probably Ledecky’s last Olympics and she entered with seven gold medals and 10 overall. Among female swimmers only American Jenny Thompson has more golds with eight, and only Thompson and Dara Torres have more medals with 12.

With Saturday’s bronze, Ledecky is one shy of that record. She already has more individual golds than any female swimmer in history and can add to that total this week in the 800 and 1,500 freestyles — she has never lost an Olympic final in either event — and the 800 freestyle relay.

No one in these Games has done more to build interest and attention for women’s swimming than she has.

“It’s awesome for the sport and awesome for women’s swimming,” she said. “It’s a testament to Ariarne and Summer and the performances they’ve had over the last few years. And I’d like to think that I contributed a little bit to the build-up around that race.

“It’s incredibly exciting to be a part of it. We could all feel the energy in the stadium today.”

Titmus, who beat Ledecky over the same distance three years ago in Tokyo, said this one felt different.

“It’s a little bit more emotional,” she said. “I know what it feels like to be an Olympic champion. I know how hard it is racing in these circumstances, at an Olympic Games. The noise, atmosphere, pressure.

“It’s not like anything else. It’s not about how fast you go. It’s about getting your hand on the wall first. I really hope all the hype lived up to the expectation.”

Not really. After briefly lining up in Ledecky’s lane when the swimmers were called to their blocks — “I had to tell her, ‘You’re in Lane 5.’ She was freaking out,” Ledecky said — the Australian turned the race into a rout from the start, building a comfortable lead by 100 meters, then seemingly lengthening it with every stroke.

By the halfway mark, Ledecky was nearly two seconds back; over the next 100 meters she dropped another second back to finish closer to New Zealand’s Erika Fairweather, the fourth-place finisher, than to Titmus.

American Caeleb Dressel shakes the hand of Australian Kyle Chalmers after a men’s 400-meter freestyle relay heat. Dressel would anchor the U.S. team to gold Saturday.

(Ashley Landis / Associated Press)

Afterward, Ledecky said she felt old next to Titmus, 22, and McIntosh, 17, as they climbed off the medal stand — especially when an Olympic official handed her a phone to take a selfie of the threesome.

“I was joking with them like, you’re gonna give the oldest person the phone to figure out how to open it up and click the right button?” Ledecky said. “Hopefully the photo turned out [OK].”

Ledecky’s bronze was one of three medals won by the U.S. on the first day of swimming.

Caeleb Dressler picked up his eighth gold and the first for the Americans at these Games by anchoring the 400-meter freestyle relay team to victory over Australia with Italy finishing third. In the women’s relay the order was reversed, with Australia winning and the U.S. finishing second, ahead of China.

In the men’s 400-meter freestyle, Germany’s Lukas Maertens held off late charges from Australia’s Elijah Winnington and South Korea’s Kim Woo-min to win in 3:41.78, less than two seconds off the oldest individual world record in Olympic swimming.