US freestyle great Katie Ledecky posted the second-fastest 400m freestyle time of her storied career on Thursday, clocking 3 minutes 56.81sec to run down Summer McIntosh for a second stunning victory in as many days at the TYR Pro Swim Series meeting in Florida.
Ledecky, who posted the second-fastest 1 500m free time in history on Wednesday, overshadowed the return to action of Paris Olympic star Leon Marchand, who posted a personal best in finishing third in the men's 400m freestyle in his first competition in four months.
With the World Championships in Singapore coming up July 27-August 3, nine-time Olympic gold medallist Ledecky produced the fastest women's 400m to date in a US pool – and her fastest since she set the American record of 3:56.46 in winning Olympic gold in Rio de Janeiro in 2016.
"I don't know if I ever thought I would be 3:56 again," a beaming Ledecky said in a poolside interview. "It wasn't even in my head for tonight for sure."
For most of the race, Ledecky was chasing McIntosh, who was under the pace of Titmus's world record through 300 metres. Ledecky stayed in touch, and as McIntosh began to fade on the penultimate lap, she pounced.
"I just tried to stick with her and just stay calm and just stick with my race, trust my tempo at the end, which is my bread and butter," Ledecky said.
Canada's McIntosh, who had traded the world record with Ariarne Titmus in 2023 before finishing runner-up to the Aussie at the Paris Olympics, finished second in 3:58.28.
The World Championships promises to be another Ledecky-McIntosh duel with Titmus on an "extended break" before resuming training in preparation for the 2028 Olympics.
Meanwhile, France's Marchand made a solid return to competition in an event that didn't feature among his four individual gold medals at the Paris Games.
The 22-year-old, who opted out of the short course world championships in December then sought a change of pace by training in Australia before rejoining coach Bob Bowman in Texas, clocked 3:48.97 to finish third in the 400m freestyle, won by American Kieran Smith in 3:47.04, with Ryan Erisman second in 3:48.57.
CASAS DOUBLE
Among other events on Thursday, American Shaine Casas won the men's 100m freestyle in 48.47 seconds, then returned to win the 50m backstroke in 24.41.
US veteran Regan Smith won the women's 200m butterfly 2:05.38 – second fastest this season behind the 2:04.00 that Olympic champion McIntosh posted in March.
Minutes after a runner-up finish in the 50m backstroke, Smith was able to hold off a pair of American teenagers in Alex Shackell and Audrey Derivaux.
American Gretchen Walsh won the women's 100m free in a career-best 52.90 seconds, edging Paris Olympics silver medallist Torri Huske (52.95). They posted the first sub-53-second times of the year.
Denis Petrashov of Kyrgyzstan, who swims in the States for the University of Louisville, won the men's 100m breaststroke in a personal best of 59.23. Lithuania's Aleksas Svickas was second in 59.72.
Austrian Martin Espernberger won the men's 200m butterfly in 1:55.71, storming from sixth at the halfway point to grab the victory over American Carson Foster, who clocked 1:55.84.