Katie Ledecky continued her build up to the Tokyo Olympics with a 400m freestyle victory at the Mission Viejo Pro Swim Series in 3min 59.25sec.
The US freestyle great, who won the 200m free on Friday in a world-leading 1:54.40, notched the 20th career performance under the four-minute mark.
"It's always good to get under four," Ledecky said. "that one probably didn't feel as good as some of my other swims this week so far, but I'm more than happy with the time."
Ledecky finished comfortably in front of Olympic bronze medallist Leah Smith (4:06.37) with Halie Flickinger (4:08.05) third.
World record-holder and 2016 Olympic gold medallist Ryan Murphy won the men's 100m backstroke in 53.11sec, ahead of Spain's Hugo Gonzalez and American Daniel Carr.
Gonzalez powered home with a strong second 50m, but settled for second in 53.76 ahead of his University of California teammate Carr (53.83).
Unlike some of the elite swimmers finding the morning finals -- instituted for this meeting to mimic the Tokyo Olympic schedule -- strange, Murphy said he enjoyed it.
"I wish every meet was morning finals," Murphy said, adding that it suited his impatient nature. "It's nice to just get up and do it."
Olivia Smoliga won the women's 100m backstroke, overtaking Kathleen Baker on the second lap to win in 59.04 -- fourth best in the world this year. Baker was second in 59.50.
In the women's 200m butterfly it was 17-year-old Katie Crom powering late past Lillie Nordmann and Katie Drabot to win in 2:10.38.
Drabot led at the halfway stage only to be overtaken by Nordmann, but neither could answer Crom's late charge.
Nordmann settled for second in 2:10.62 and Drabot was third in 2:10.94.
Bruno Fratus won the men's 50m freestyle in 21.80, with US star Caeleb Dressel second in 21.83.
The time, in a meet the Brazilian swimming federation said would serve as the US-based Fratus's Olympic selection opportunity, could be enough to punch the Brazilian's ticket to the Tokyo Games, but he'll have to await the results from the Brazilian trials in two weeks to know for sure.
In other events, Lilly King went out fast and held on to win the 200m breaststroke in 2:22.38, adding it to her 100m breaststroke win on Friday.
Nic Fink completed a men's breaststroke double, winning the men's 200m in 2:09.73.