Gold Coast - American Katie Ledecky set her second world record in two days by shattering her own 1 500-metre freestyle record at the Pan Pacific Championships on Sunday.
The 17-year-old schoolgirl broke her record by almost six seconds with a time of 15 minutes 28.36 seconds to claim her fifth gold medal at the Gold Coast meet.
Ledecky had only set the previous record in the non-Olympic event in June with 15:34.23.
The wonder teen smashed the 400m freestyle world record at this meet on Saturday, clocking 3:58.37 to beat her previous mark by 0.49sec.
Ledecky holds the world records in the 400m, 800m and 1500m freestyle, making her the first woman since US distance great Janet Evans to hold all three records at the same time.
Ledecky has won the 200m, 400m 800m and 1500m freestyle golds at the Pan Pacs and was also part of the American women's winning 4x200m freestyle relay team.
She beat New Zealand's Lauren Boyle by more 10 seconds in winning the 1500m gold and was well under world record pace during the middle stages of the 30-lap final.