Australian teenager Ariarne Titmus ended the great Katie Ledecky's perfect 400 metre freestyle record at major international events to take gold at the World Aquatics Championships in Gwangju on Sunday.

American Ledecky had only failed to be crowned world champion on one occasion when she had to settle for 200m silver in Budapest two years ago.

The 22-year-old was unable to add to her tally of 14 World Championships golds in South Korea, though, as Titmus passed her with only a few metres to go and held on dethrone Ledecky with a magnificent swim.

Titmus touched the wall in 3:58.76 to claim her maiden long-course world title.

Legendary duel between Australia’s Ariarne Titmus and Katie Ledecky of USA in the Women’s 400m Freestyle! Titmus overtaking Ledecky with only a few meters to go, winning in 3:58.76. All the action live on https://t.co/bEozhdW5qV #FINAGwangju2019 #Swimming #FINA pic.twitter.com/xknw7yMLxH

— FINA (@fina1908) July 21, 2019

"I knew that I properly had that in me." said the 18-year-old Tasmanian.

Great Britain's Adam Peaty smashed his own 100m breaststroke world record by clocking 56.88 in the semi-finals.