Summer McIntosh broke her own world junior record as she retained women's 200m butterfly title in Fukuoka ©Getty Images

Canadian teenager Summer McIntosh powered to victory at the Fukuoka 2023 World Aquatics Championships as she retained her women's 200 metres butterfly title.

The 16-year-old captured the gold medal with a time of 2min 4.06sec to beat Australia's Commonwealth Games champion Elizabeth Dekkers.

American Regan Smith took the bronze but all eyes were on McIntosh who finished with 1.40 seconds to spare and smashed her own world junior record.

Triple Olympic gold medallist from Tokyo 2020 Kaylee McKeown began a gold rush for Australia as she finished the women's 50m backstroke in 27.08.

Smith once again medalled but was just 0.03 off top spot while Britain's Lauren Cox came third with 27.20 on the clock.

McKeown's compatriot and fellow Olympic champion Kyle Chalmers then backed up her victory with a 47.15 win in the men's 100m freestyle over American Jack Alexy and France's Maxime Grousset by 0.16 and 0.27, respectively.

A world record time from Mollie O'Callaghan, Shayna Jack, Brianna Throssell, and Ariarne Titmus then followed for Australia in the women's 4x200m freestyle relay.

The quartet finished in 7:37.50 to beat the United States and China with respective times of 7:41.38 and 7:44.40.

The final swimming triumph of the day went the way of Frenchman Léon Marchand in the men's 200m after 1:54.82 before the British duo of Duncan Scott and Tom Dean followed suit in second and third.

A Romanian one-two was in store in the men's 27m high diving event with Constantin Popovici leading the way on 472.80 points.

His countryman Catalin-Petru Preda took silver, 34.35 points off the lead, while France's Gary Hunt made up the top three with 426.30.