Budapest (AFP) - Katie Ledecky earned a second gold medal on Sunday at the world aquatics championships in Budapest by helping the United States win the women's 4x100m freestyle final.
Sweden's Sarah Sjostrom had set a world record of 51.71sec in the opening leg, becoming the first woman to break the 52-second barrier.
The USA clocked three minutes, 31.72 seconds with Australia taking silver at 0.29secs back, while the Netherlands earned bronze at 0.92.
Ledecky finished the opening day of the world champs with two golds after her victory in the women's 400m freestyle final earlier at the Duna Arena.
The US were third midway through Ledecky's leg, but the 20-year-old blasted through the final 50 metres to give her team the lead.
She handed over to Simone Manuel, the joint 100m freestyle champion at the 2016 Olympics, who touched the wall just ahead of Australia's Emma McKeon.
Sjostrom's Sweden finished fifth despite a sensational opening 100 metres, beating the previous record of 52.06sec set by Australia's Cate Campbell in 2016.
That is the biggest world record improvement in this event since Libby Trickett of Australia beat Britta Steffen's mark by 0.42 in 2008.