FUKUOKA, Japan -- Katie Ledecky won the 1,500-meter freestyle with ease on Tuesday at the World Aquatics Championships in a landmark victory that made her the most decorated female swimmer at the worlds with 20 golds overall, 15 in individual events.

That ties Michael Phelps' record at the worlds for individual gold medals.

American Ryan Murphy added the second American gold medal Tuesday, winning the 100-meter backstroke. But as usual when the 26-year-old Ledecky swims, she's the story.

Ledecky has won seven Olympic golds, the first coming more than a decade ago in London. And she's talking about racing not just in next year's Paris Olympics, but perhaps also in Los Angeles in 2028.

"I never dreamed of winning one Olympic gold," Ledecky said. "So after I did it, it was like, 'OK, the rest is icing on the cake, a cherry on top,' whatever you call it. I'm just trying to build a really big cake, I guess."

That cake is getting bigger for one of the greatest freestylers the sport has ever seen.

She won Tuesday in 15 minutes, 26.27 seconds, the third-quickest time of her career.

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"The last couple of years I've just tried to be really locked in on my stroke," said Ledecky, who has been improving quickly post-pandemic. "That was a really good performance from me -- very pleased."

Italy's Simona Quadarella finished 17 seconds behind Ledecky in 15:43.31, with Li Bingjie of China third in 15:45.71.

Ledecky will compete in the 800 on Saturday -- her favorite race -- and is set to become the only person to win six titles at the worlds in the same event.

Murphy, a four-time Olympic gold medalist and the defending world champion in the 200 backstroke, edged Italian Thomas Ceccon by .05 seconds. Murphy clocked 52.22 and Ceccon 52.27, with bronze for American Hunter Armstrong in 52.58.

"It's awesome to go against a great field, and it's awesome to get two Americans on the podium," Murphy said. "The USA is off to a start. We're starting to build some momentum and we can just keep it rolling from here."

The big shock was 18-year-old Romanian David Popovici, who was a clear favorite in the 200 free. He finished fourth behind two British swimmers -- Matthew Richards in 1:44.30, and Tom Dean in 1:44.32. South Korean Hwang Sunwoo took bronze (1:44.42) with Popovici finishing fourth in 1:44.90.

"It felt awful," Popovici said. "But that means that we can improve something and that's a good thing. Because if you have the absolute perfect race … you have nothing else to improve.

"I'm glad it happened now and I'm sure it has a meaning and I'm going to learn from it."

Ruta Meilutyte of Lithuania captured gold in the women's 100 breaststroke in 1:04.62, ahead of Tatjana Schoenmaker of South Africa and third-place Lydia Jacoby of the U.S. World-record holder Lilly King was fourth. The American finished in 1:06.02.

Kaylee McKeown of Australia won the women's 100 backstroke in 57.53, edging Regan Smith of the United States by 0.25. American Katharine Berkoff took third in 58.25.

McKeown was disqualified earlier in the 200 IM for a violation on the backstroke leg, infuriating her and her team.

"If you're not learning you're not growing," she said. "So I had to find a positive in a negative and that's what I did. I channeled it and I managed to make it work. Being up against the Americans, they bring out the best."