The Australian had already secured a gold medal in the women’s 200 metres freestyle event at the Hangzhou Olympic and International Expo Centre.

She powered to victory over the longer 400m distance today, touching home in a short course world record of 3min 53.92sec.

China’s Wang Jianjiahe and Li Bingjie rounded off the podium in front of a home crowd, as they finished in 3:54.56 and 3:57.99 respectively.

"I can't believe it, and for it to be a short course world record is something," said Titmus.

"I am someone who does not pride themselves on speed, but I will take it."

Titmus was the only athlete to produce an individual world record on the fourth day of the Championships, which proved a productive one for Russia.

Vladimir Morozov secured gold in the men’s 50m freestyle final, the Russian producing a time of 20.33sec.

He was followed by the United States’ Caeleb Dressel in 20.54, while South Africa’s Brad Tandy ended third in 20.94.

Morozov’s compatriot Kliment Kolesnikov, a star of the Buenos Aires 2018 Summer Youth Olympics, triumphed in the men’s 100m individual medley.

The Russian achieved a Championship record time of 50.63 to take gold, with Marco Orsi of Italy proving his closest challenger in 51.03.

Japan’s Hiromasa Fujimori completed the podium in a time of 51.53.

Katinka Hosszú continued her successful Championships by winning a third gold medal, as the Hungarian achieved a time of 57.26 in the women’s 100m individual medley.

Runa Imai of Japan took silver in 57.85, while Jamaica’s Alia Atkinson was the bronze medallist in 58.11.

Dutch star Ranomi Kromowidjojo secured her second gold medal of the Championships, as the 100m freestyle champion won the women’s 50m butterfly.

A Championship record time of 24.47 saw Kromowidjojo claim victory, followed by Australia’s Holly Barratt and the United States’ Kelsi Dahlia completing the podium.

They trailed the winner home in times of 24.80 and 24.97 respectively.

World records fell in the two relays contested on the day, with the US triumphing in the men’s 4x50m event.

Their team completed the distance in a time of 1:21.80 to finish top of the podium.

Russia and Italy completed the podium, clocking 1:22.22 and 1:22.90 respectively.

Brazil produced a world record 6:46.81 to win the men’s 4x200m freestyle relay, while Russia and China managed 6:46.84 and 6:47.53 to clinch the minor medals.

The Championships are due to continue tomorrow.