NANTERRE, France — American Regan Smith versus Australian Kaylee McKeown never seems to get old, whether they're competing in the same race or on opposite sides of the globe. 

And Tuesday’s women’s 100-meter backstroke final — one of the most highly anticipated swimming showdowns at the 2024 Paris Olympics — didn’t disappoint. McKeown out-touched Smith by .33 seconds to win her second consecutive 100 back Olympic gold. 

Smith, 22, won silver with a time of 57.66, and fellow American Katharine Berkoff, 23, won bronze with a 57.98 swim at Paris La Défense Arena.

McKeown, 23, broke her own Olympic record with a time of 57.33, lowering the mark by .14 seconds, and became the first swimmer to successfully defend her 100 back Olympic title since American Natalie Coughlin at the 2004 and 2008 Games.

“She's one of one,” Smith said about McKeown. “She is an absolutely incredible racer, and she knows what to do when it matters.”

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Of the medalists, Smith was first off the block and was tied for the lead at the 50-meter mark with Canada’s Kylie Masse. McKeown was fourth at the turn before exploding on the last 25 to take the lead and ultimately gold.  

“You wait for that moment so much, and then you get to the race and you finish the race, and I can't even remember it now,” said McKeown, who’s also the defending OIympic champion in the 200-meter backstroke. 

“But I knew it would come down to that last 25 meters. It's something that I've been practicing for, and something that the Americans and myself are really good at — is finishing our races strong. So it’s just gonna be whoever had it in that last five, 10 meters.”

While the 2021 Olympic record fell — albeit to the previous owner — Smith’s 57.13 world record remains intact. But she and McKeown have been fighting over it for a while. 

In the last five years, both swimmers have broken the 100 back world record twice. Smith broke it in 2019, McKeown took it in 2021 before lowering it again in 2023, and Smith reclaimed it in June at U.S. Olympic trials. 

“I want to call it a rivalry because we have traded world records,” Smith said, “but she's always good at getting it done when it matters. So I want to give her the credit where it's due. 

“But with that being said, yeah, I'm incredibly proud that we have really solidified ourselves as the two fastest women in backstroke history, and that's really special to be a part of. … She’s a very genuine and respectful person, and I think we have a really great relationship.”

The 100 back final was always going to be a close race in the latest chapter of the decades-old storied USA-Australian swimming rivalry with Smith, McKeown and Berkoff, respectively, qualifying within .30 seconds of each other in Monday’s semifinals. 

Masse — the 2021 Tokyo silver medalist and 2016 Rio bronze medalist in the 100 back — finished fourth, and Australia’s Iona Anderson was fifth. 

A two-time Olympian, Smith won her fourth medal at the Games, but she’s still racing for her first gold. At the 2021 Tokyo Olympics, she was the 100 back bronze medalist and won two silvers in the 200-meter butterfly and women’s 4x100-meter medley relay. 

“I'm proud that I was able to drop [time] from semis,” said Smith, who shaved off .31 seconds in the final. “That's something that I've struggled with a lot in the past, and I stayed in my own lane, I executed my race plan and I left it all in the pool.”

First-time Olympian Berkoff made history of her own in Tuesday night’s final. Her bronze was both Team USA’s 3,000th Olympic medal and USA Swimming’s 600th OIympic medal, according to the U.S. Olympic and Paralympic Committee. 

She’s also not the first member of her family to earn some hardware at the Games. Her father, David Berkoff, is a four-time Olympic medalist and won the men’s 100 back silver in the 1988 Seoul Games and bronze in 1992 in Barcelona.

“He's been very supportive, just trying to remind me to stay in my own lane, remember why I'm doing what I'm doing and just do it for myself and no one else,” Berkoff said. 

“I'm so grateful that he got to be here to watch it.”

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