Australia’s Ariarne Titmus caused a real upset in the 400m freestyle, beating hot favourite Katie Ledecky to take gold in a stunning finish.
Titmus chased down the American superstar with a personal best and national record to win in 3:56.69 and secure Australia their second gold medal.
It was the first time Ledecky, 24, has lost an individual Olympic race in her career.
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Ledecky was roughly one body length in front at the halfway point, leading by 0.66 seconds with 200m left. But Titmus stormed back in the final 50m and beat Ledecky’s time of 3:57.36.
China’s Li Bingjie took third with a time of 4:01.08.
Titmus, 20, said after the race: "I can’t believe it, I’m trying to contain my emotions. More than anything it’s relief to do the job... I wouldn’t be here without her (Ledecky) setting the standard.
I’ve just been trying to chase her. She’s really fun to race. I can’t believe I actually pulled it off!
Titmus' coach Dean Boxall celebrated wildly in the stands after the shock win and Titmus swore when she looked up at the screen to realise she had become an Olympic champion.
Lizzie Simmonds on commentary said: "Lidecky has had that 100m taken away from her in the last 100m.
What a finish from Titmus and what confidence to go in there not needing to be leading the whole way through, Lidecky absolutely took control of that race.
"Titmus had something in reserve that Lidecky didn’t and we saw that in the last 75 metres."
Ledecky and Titmus will go head-to-head again in the 200 metres freestyle on Wednesday.
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