KAZAN, Russia (AP) — Katie Ledecky of the United States has lowered her own world record by 2.23 seconds in winning the 1,500 freestyle at the world swimming championships.

The 18-year-old swimmer led all the way and touched in 15 minutes, 25.48 seconds Tuesday night. That improved her mark of 15:27.71 set in the preliminaries of the non-Olympic event on Monday.

Ledecky raised her right arm in celebration of her second consecutive world title in the event and smashed the water while her teammates cheered in the stands. She got out of the pool and immediately headed to the warm-down pool and began swimming laps.

Lauren Boyle of New Zealand finished second in 15:40.14. Boglarka Kapas of Hungary took third in 15:47.09.

Lotte Friis of Denmark, runner-up to Ledecky two years ago in Barcelona, finished fourth.