Katie Ledecky closed USA Swimming's World Championship trials with a fourth victory on Saturday, producing yet another dominant win in the 1,500m freestyle.

The distance freestyle phenomenon clocked 15min 38.99sec, improving on her own world leading time of the season to beat Katie Grimes by 12.37sec.

It was the 15th-fastest performance in history. Ledecky herself owns 13 of the 14 fastest times ever swum, and the seven-time Olympic gold medalist sounded a little disappointed that it wasn't better.

"It was decent," said Ledecky, who had notched victories in the 200m, 400m and 800m freestyles this week in Greensboro, North Carolina, in the qualifying meet for the World Championships in Budapest June 18-July 3.

"I would've liked to have been a little bit faster, but I'll take it at the end of the week."

Caeleb Dressel, who won five Olympic gold medals in Tokyo to take his career tally to seven, also won his fourth event of the meet on Saturday, clocking a world-leading 21.29sec in the 50m free ahead of Michael Andrew, whose 21.45 was second-quickest of the season.

Olympic silver medalist Alex Walsh won the women's 200m medley in a world leading 2:07.84. Leah Hayes, 16, was second in 2:09.99. She booked a World Championships berth after being initially disqualified for a false start in the heats but then reinstated for a spot in the final.

Chase Kalisz, the reigning 400m individual medley Olympic champion, won the men's 200m medley in 1:56.21 to line up a medley double bid in Budapest. Carson Foster -- who relegated Kalisz to second in the 400 IM earlier this week, was second in 1:56.65.