Australia's Ariarne Titmus has upset American great Katie Ledecky to claim 400m freestyle gold at the world swimming titles in South Korea.
Titmus, 18, powered past five-time Olympic champion Ledecky on the final lap on the opening night of the eight-day titles at Gwangju.
She clocked three minutes, 58.76 seconds to beat Ledecky by 1.21 seconds, denying the American a fourth straight 400m world title.
Remarkably Ledecky - a 14-time world champion - had not been beaten over 400m, 800m or 1500m freestyle at a major international meet since 2012.
"I feel pretty normal, it was just a swimming race," Titmus said after her stunning win.
"There was no pressure really coming into this race. I just wanted to fight as hard as I could - in that last 50m I gave it everything."
Titmus led through the first 200m and at one stage was under world-record pace before Ledecky made her move.
The American hit the front with 250m left and looked set to power home before Titmus put on the afterburners in a stunning final lap finish.
"I knew I had to take it out hard to be with her. Her third 100m is still a lot better than mine but suddenly I felt something," Titmus said of her final surge.
Ledecky finished second in 3:59.97 - well off her world record of 3:56.46 set at the Rio Olympics.
American Leah Smith took bronze in 4:01.29.
Australian Associated Press
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