The seven-time Olympic champion equalled the record of 15 set by compatriot Michael Phelps when she captured the women’s 1,500 metres freestyle crown before breaking it with victory in today’s women’s 800m freestyle final.

The success also saw Ledecky become the first swimmer to win any event on six occasions at the World Championships.

Ledecky was in a class of her own as she clinched gold in a time of 8min 8.87sec, seeing off China’s Li Bingjie who posted an Asian record of 8:13.31 for silver.

The bronze medal was won by Australia’s Ariarne Titmus who equalled the Oceania record with 8:13.59 to finish third.

"It was special," said Ledecky.

"I’m happy with that swim.

"I wanted to be a little bit better, but I’ll take it.

"I’m really pleased with how the week went."

Ledecky’s record-breaking triumph was part of a memorable penultimate day at the Marine Messe Fukuoka.

Sweden’s Sarah Sjöström had a day to remember as she sealed a fifth successive women’s 50m butterfly title – a streak that started in 2015.

Sjöström emerged victorious in 24.77 as China’s Zhang Yufei posted an Asian record of 25.05 for silver and Gretchen Walsh of the US bagged bronze in 25.46.

There was further delight for Sjöström when she broke the world record in the women’s 50m freestyle in the semi-finals.

The Swede lowered her previous record mark by 0.06 after touching the wall in 23.61.

Kaylee McKeown of Australia completed a clean sweep of women’s backstroke titles after triumphing over 200m today.

The three-time Olympic champion added to her 50m and 100m golds with victory over 200m in 2:03.85.

American Regan Smith came up short for a third time in finals against McKeown as she posted 2:04.94 for silver, while China’s Peng Xuwei registered 2:06.74 for bronze.

McKeown’s victory means she is only the second swimmer to win all three distances at a single World Aquatics Championships after China’s Qin Haiyang became the first to do so following his success in the men’s 50m, 100m and 200m breaststroke in this tournament.

"That means a lot," said McKeown.

"I didn’t think I’d be able to do that tonight, especially after a long week.

"That is the best thing about sport, you have to focus on your own race, and that is exactly what I did tonight."

It was one of three golds for Australia as they came out on top in the mixed 4x100m freestyle relay and Cameron McEvoy claimed men’s 50m freestyle gold.

McEvoy posted an Oceania record of 21.06 to seal the title, beating American Jack Alexy and Britain’s Ben Proud who finished it in 21.57 and 21.58 respectively.

Australia broke the world record in the mixed 4x100m freestyle to secure gold after clocking 3:27.96.

Mollie O’Callaghan, a gold medallist in the women’s 100m and 200m freestyle, was part of the winning team along with Shayna Jack, Meg Harris and Emma McKeon.

The US sealed silver in 3:31.93, with China clocking 3:32.40 - an Asian record - for bronze.

Maxime Grousset was the other gold medallist in the pool after registering a French record time of 50.14 for the men’s 100m butterfly title.

There was also a national record for Canada’s Josh Liendo as he posted 50.34 for silver, while American Dare Rose bagged bronze in 50.46.

Hungary secured their fourth men’s water polo crown and first in 10 years after beating Greece in a shootout.

The first quarter saw Hungary open up a 4-1 lead before Greece hit back by edging the next two periods to level the match.

After drawing the last quarter, the match was locked at 10-10 before Hungary won the shootout 4-3 to win the title.

Spain, who triumphed in 2022, claimed bronze after beating Serbia 9-6.