Canadian Summer McIntosh won the 400m freestyle — the first of her two head-to-heads with Katie Ledecky — to open her bid to win a record-tying five individual gold medals at the World Swimming Championships.
McIntosh, an 18-year-old who bagged three golds at the 2024 Olympics, clocked 3 minutes, 56.26 seconds, beating China’s Li Bingjie by a comfortable 1.95 seconds.
Ledecky took bronze in Singapore for her 27th career World Championships medal, tying Ryan Lochte for second in history behind Michael Phelps’ 33.
McIntosh broke the 400m free world record in 2023 and again last month, when she took it down to 3:54.18.
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The 400m free was the lone event that McIntosh didn’t win at the Paris Games, taking silver behind Australian Ariarne Titmus (who is taking a break in 2025) and ahead of Ledecky.
McIntosh has four individual events left at these worlds: 200m and 400m individual medleys, 200m butterfly and the 800m free with Ledecky (which the American has never lost at a major meet).
“The way my freestyle is feeling, it’s feeling really strong, and I feel like my endurance is really good right now, so really hyped for the 800m freestyle,” McIntosh said on Peacock.
She can become the second swimmer to win five individual golds at a single worlds after Phelps.
Ledecky has won a 400m free medal every time she has raced it at the Olympics or worlds — 10 times dating to 2013.
She was in position for silver going into the last 50 meters, then was passed by Li, who went from fourth to second in an Asian record time.
“I would have loved to have been better,” Ledecky said. “I was a little too focused on the race on the one side. I missed Li on the other side of me, but kudos to her for getting in there. She’s been a great competitor all these years. Happy to get the medal.”
Katie Ledecky eyes the longest reign in World Championships history. Summer McIntosh wants to end it.
Also Sunday, Australia swept the women’s and men’s 4x100m free relays by overtaking the leading Americans in the last 50 meters.
In the women’s final, Australian Olivia Wunsch went past American Torri Huske to prevail by 44 hundredths. Huske raced out in the first 50, erasing the Aussies’ lead of 61 hundredths after the first three legs.
Huske, the Olympic 100m fly gold medalist, was among the U.S. swimmers who became sick at a pre-worlds training camp in Thailand. A majority of U.S. swimmers were affected to varying degrees by acute gastroenteritis, or a stomach bug.
In Sunday’s morning preliminary heats session, Huske scratched out of the 100m fly to prioritize the relay, according to USA Swimming. She can still race the 50m and 100m frees later in the meet, plus more relays.
Gretchen Walsh, 100m free runner-up to Huske at the U.S. Championships, was a late scratch from the relay final after tying for the win in her 100m fly semifinal.
In the men’s relay, nine-time Olympic medalist Kyle Chalmers overtook American rookie Jonny Kulow on anchor with the fastest split of the 32-swimmer field. Italy also passed the U.S. for silver.
German Lukas Martens took the men’s 400m free by two hundredths over Australian Sam Short in 3:42.35.
Martens, the Paris Olympic gold medalist, broke the world record in the event in April, clocking 3:39.96. He took down the longest-standing individual world record set by fellow German Paul Biedermann in 2009.
Martens wins men’s 400m freestyle at worlds
Germany’s Lukas Martens won the men’s 400m freestyle final with a time of 3:42.25 at the 2025 World Aquatics Championships in Singapore.
China’s 12-year-old Yu Zidi was seventh in the women’s 200m IM semifinals. She qualified to become the youngest finalist in World Championships history, according to Olympic historian Bill Mallon of the OlyMADMen.
Worlds continue all week with preliminary heats at 10 p.m. ET and finals at 7 a.m., live on Peacock.
Monday’s finals are expected to feature world record holders McIntosh in the 200m IM and Walsh in the women’s 100m fly.
The World Swimming Championships air live on Peacock from July 26-Aug. 3.
