RIO DE JANEIRO - The last time a women's 200m freestyle world champion also held the Olympic title, American Katie Ledeckywas not yet born.

On Tuesday, the 19-year-old world champion matched East German Heike Friedrich's 1988 feat, winning Olympic gold in 1min 53.73sec.

Sweden's Sarah Sjostrom, the top qualifier who on Sunday won the 100m butterfly gold in a new world record, took silver (1:54.08) in the highly-anticipated race at the Olympic Aquatics Stadium. Australia's Emma Mckeon claimed bronze (1:54.92).

Italy's world record holder Federica Pellegrini, the 2008 Olympic gold medallist and two-time world champion in this event, was fourth (1:55.18).

"That was a really tough race and it hurt really badly," Ledecky said. "Pretty sure that's the closest I've come to throwing up in the middle of a race. I'm just so glad I got my hand on the wall first."

Ledecky has yet to lose in a major individual final. This is her 10th individual victory at the Olympics and world championships.

With compatriot Michael Phelps, the most decorated Olympian of all time, making his fifth and final Games appearance, Ledecky has provided further evidence that she is primed to become the new face of swimming.

On Sunday, she won 400m free gold in world-record time. She also has an 800m free gold from the 2012 London Games. She will begin that title defence on Thursday.

"Ledecky is one of a kind," said Sjostrom. "It feels like gold that I'm after her. I couldn't have gone any faster, it's impossible."

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