Katie Ledecky's 800 free win breaks golds tie with Michael Phelps - ESPN

Katie Ledecky showed she was at the peak of her powers at the age of 26, winning the women's 800-meter freestyle on Saturday to retain her title and surpass Michael Phelps with a record 16th individual gold at the world championships.

Ledecky led from start to finish and touched the wall in 8:08.87, four seconds outside of her 2016 world record, to become the first swimmer to win a single worlds event six times — doing so consecutively as well.

It was Ledecky's second gold at these worlds, along with winning the 1,500 free earlier this week, giving her 21 worlds golds overall.

She went 4.44 seconds faster than silver medallist Li Bingjie of China, with Australia's Ariarne Titmus collecting bronze.

Sarah Sjoestroem cruised to her fifth straight world title in the women's 50 butterfly before breaking the world record in the 50 freestyle in the semifinals.

The 29-year-old Sjoestroem finished the day's opening event in 24.77 seconds to hold off China's Zhang Yufei, who was 0.28 seconds behind. Gretchen Walsh of the United States took bronze.

«That was amazing, I'm very proud of this gold, which is the fifth one. It's amazing,» said Sjoestroem, who tied Phelps with 20 individual medals at the world championships. «I feel like I enjoy it more than ever at the moment.»

Sjoestroem then produced a superb effort of 23.61 seconds in the freestyle to better her own mark of 23.67 seconds, which she had set in the 2017 worlds in Budapest.

Another world record fell when the Australian mixed 4x100m freestyle relay team of Jack Cartwright, Kyle Chalmers, Shayna Jack and Mollie O'Callaghan lowered their world record in the final race of the evening as they finished in 3:18.83.

Australia's Olympic and world champion Kaylee McKeown sealed a