American Regan Smith came into the women's 100-meter backstroke at the Paris Olympics with the world record and no shortage of confidence.

At the turn Tuesday night, it was Smith in the lead with McKeown right on her heels. By the time they reached the other end of the pool, it was the Aussie lunging there first.

McKeown still rules the backstroke.

“She is an absolutely incredible racer and she knows what to do when it matters,” Smith said.

Smith, who broke McKeown's world mark with a time of 57.13 seconds at the U.S. trials last month, led at the turn but couldn't hold off the hard-charging Aussie, who defended the title she won in Tokyo three years ago.

McKeown surged to the front about halfway through the return lap and reached for the wall in 57.33, winning by a relatively comfortable margin over Smith's finish of 57.66.

“The nerves were definitely there but I just reminded myself it's a pool in a different venue, and I train every single day of my life,” McKeown said.

The U.S. also grabbed the bronze as Katharine Berkoff touched third in 57.98, capturing her first Olympic medal and following in the footsteps of her father, David Berkoff, who won four medals — two of them gold — in Seoul and Barcelona .

Smith reached over the lane rope to congratulate McKeown, but this one had to sting. The 22-year-old Minnesota native appeared to be in top form and primed to win her first gold medal.

Instead, it was McKeown capturing her fourth gold overall. She swept the backstroke events in Tokyo and also claimed a relay gold.

“It's one race at a time,” McKeown said. "I've checked off three boxes so far and there's a few more to go.”

American swimmers are getting used to silver

It was a night of silvers for the Americans, who took the runner-up spots in all three of the finals.

Bobby Finke came up short in defense of his Olympic title in the men's 800 freestyle, relegated to silver by Ireland's Daniel Wiffen.

The Americans also finished second in the men's 4x200 freestyle behind Britain, which captured its second straight gold in that event.

Through four days at La Defense Arena, the U.S. has a bunch of medals — 15 in all — but only two of them are gold. Seven silvers and six bronzes round out the tally.

Irish win first swimming gold since 1996

Wiffen won Ireland's first gold medal in swimming since scandal-plagued Michelle Smith finished first in three events at the 1996 Atlanta Olympics.

Wiffen surged past Italy's Gregorio Paltrinieri on the final lap, looking as fresh as he did at the beginning of the grueling race.

Actually, he was in excruciating pain.

“I was dying the last 20 meters,” Wiffen said. “I'm not sure if you saw that, because my arms are in absolutely so much pain. But I knew that the crowd is gonna carry me in, and that's exactly what happened. Then I saw the red light on the block, and that was it.”

Wiffen won in 7 minutes, 38.19 seconds, climbing on the lane ropes to hold one finger skyward. Finke also came on strong late in what was essentially a three-man race, also passing Paltrinieri to take the silver in 7:38.75.

The bronze went to the Italian, who posted a time of 7:39.38.

It was another dazzling performance by an Irish swimmer, on the heels of Mona McSharry grabbing a bronze in the 100 breaststroke the previous night.

Until these Olympics, the country's swimming history was essentially confined to Smith, who surprisingly claimed three golds and a bronze in 1996 amid suspicions she was doping. She later received a doping ban that essentially ended her career, but she kept her medals.

British men defend their relay title

The British men defended their title in the 4x-200 freestyle relay, holding off the United States and Australia.

The team of James Guy, Tom Dean, Matthew Richards and Duncan Scott -- the same foursome that captured gold in Tokyo three years ago -- finished in 6:59.43.

The only difference from the last Olympics was Dean took the leadoff, with Guy going second. It was good enough for another gold, Britain's first swimming victory of the Paris Games.

Luke Hobson, Carson Foster, Drew Kibler and Kieran Smith gained a bit of redemption for the Americans with a silver medal in 7:00.78, making up for a disappointing fourth-place showing at the last Olympics.

Maximillian Giuliani, Flynn Southam, Elijah Winnington and Thomas Neill earned the bronze for Australia in 7:01.98.

Doubling up

French star Léon Marchand had a very busy day, advancing to the final in both the 200 butterfly and 200 breaststroke.

Marchand did a double in the morning preliminaries, then gutted through another back-to-back in the evening semifinals with about 80 minutes between races.

He posted a time of 1:53.50 in the fly semis, trailing only defending Olympic champion and world-record holder Kristóf Milák of Hungary (1.52.72). Marchand was faster than everyone in the breaststroke round, posting a time of 2:08.11 with another raucous home crowd cheering him on.

Marchand will have to double up one more time in the finals Wednesday, looking to add to the gold he earned in the 400 individual medley.

“The French crowd has been amazing for me,” he said. "I'm just really lucky to be in good shape this week to swim as fast as possible.”