China's Jianjiahe Wang set a new world record in the women's 400 metres freestyle at the International Swimming Federation (FINA) Swimming World Cup in Budapest.
The 16-year-old swam her race in 3mins 53.97secs, the first woman to swim 400m at the 3:53 mark.
“I wasn't aware of the splits, I just wished to follow the plan my coach set up for me," Wang said after her display at the Duna Arena.
"I'm really happy now."
Australian Mack Horton won the men's 400m freestyle event.
Another record was set when Hungarian Katinka Hosszu won her 400th World Cup medal in front of a home crowd.
She won the 100m individual medley race, beating rival Sarah Sjostrom of Sweden by 0.11 seconds.
Hosszu then won a second gold in the 200m fly event.
Vlad Morozov of Russia also achieved a double in the 100m individual medley and in the 50m freestyle event.
There was a surprise in the women's 50m freestyle when 2012 Olympic champion Ranomi Kromowijojo from The Netherlands beat Sjostrom by 0.13sec.