LOS ANGELES, June 17, 2024 (BSS/AFP) - Newly minted world record-holder Gretchen Walsh punched her ticket to the Paris Olympics on Sunday with a victory in the women's 100m butterfly in a blistering 55.31sec.

The 21-year-old Tennessean couldn't match the astonishing 55.18 she threw down in the semi-finals to shatter Sarah Sjoestroem's previous mark of 55.48 -- but she clocked the second-fastest time ever and completed the most important job of the week in securing her first Olympic berth.

"I'm still in shock," Walsh said. "I don't even know what to say. Making the team was the biggest goal, but getting a world record was absolutely insanity."

Torri Huske, the 2022 world champion who was shut out of the medals at the Tokyo three years ago, finished second in her lifetime best 55.52 -- fourth-fastest ever -- to line up another Olympic shot.

But former backstroke world record-holder Regan Smith will have to look to her other events after finishing third in 55.62.

The trio of contenders showcased the cut-throat nature of the US trials, in which only the top two finishers can book individual berths for Paris.

Smith's time tied her for fifth-fastest all-time in the event but just wasn't enough.

The tension-packed meet has a suitably spectacular venue in Lucas Oil Stadium, home of the NFL's Indianapolis Colts.

The second night of action opened with 22-year-old Carson Foster, who missed out on the Tokyo Games with a third-placed finish at trials, winning the 400m individual medley to punch his long-awaited ticket to Paris ahead of Tokyo gold medallist Chase Kalisz.

Foster led all the way to win in a sizzling 4min 07.64sec, Kalisz narrowing the gap on the breaststroke and freestyle legs to finish second in 4:09.39.

It was an emotional triumph for Foster, who led at the 350-meter mark at the trials for Tokyo only to be run down by Jay Litherland, who snagged the second Olympic berth and took silver in Tokyo behind Kalisz.

This time Litherland was left on the outside looking in after finishing third.

In Paris the Americans will be gunning for French world record-holder Leon Marchand, who is set for a star turn in home waters.

Veteran Nic Fink, 30, secured his Olympic berth, hanging on for a victory in the men's 100m breaststroke in 59.08 with Charlie Swanson second in 59.16.

In semi-final action, world record-holder and 2016 Rio gold medallist Lilly King topped the times in the women's 100m breaststroke, her 1:05.67 the only performance under 1:06.

King, an Indiana native, received a thunderous ovation as she walked to the blocks -- a reception amplified in the massive venue.

"I felt like I was walking out to a boxing match," said King, who will be up against a field including Tokyo gold medallist Lydia Jacoby in Monday's final.

Freestyle great Katie Ledecky, already headed to a fourth Olympics after her victory in the 400m freestyle, topped the 200m free semi-final times in 1:55.25.

There was drama in the men's 100m backstroke semis, with top-seeded Hunter Armstrong slipping at the start and turning last but powering home to finish second in his semi and secure his spot in the final.

Ryan Murphy, who won double backstroke gold in Rio in 2016 led the way into the final in 52.65.