Kate Douglass continued her assault on the 50m freestyle world record on Saturday, clocking a stunning 23.19sec to win Pan Pacific Championships gold with her second world mark of the day.
The American sliced three-tenths of a second off the world record of 23.49sec she set hours earlier in the heats in Irvine, California.
That broke the world record of 23.55sec set by fellow American Gretchen Walsh on 28 June in Rome – where Walsh broke the world mark that Douglass had set on 19 June.
Douglass finished a whopping 55-hundredths of a second ahead of Walsh, who took silver in 23.74sec. Australia's reigning world champion Meg Harris was third in 23.89.
Douglass returned less than half an hour later to claim silver in the 200m breaststroke won by Canadian Alexanne LePage in 2:21.73.
Douglass, the reigning world and Olympic champion in the event, closed strong to finish second in 2:22.57.
Australian Jamie Jack won the men's 50m free in 21.35sec and Zac Stubblety-Cook rallied from fourth at the final turn to win the men's 200m breaststroke in 2:08.09 and give Australia another gold in the four-day meeting that brings together top swimmers from non-European countries.
Chinese Olympian Yu Yiting started the night with an upset of world record-holder Summer McIntosh in the 200m medley, leading most of the way and holding off the Canadian's charge on the final freestyle leg to win in 2:07.45.
McIntosh, the reigning world and Olympic champion, was third after the penultimate breaststroke leg and her late charge wasn't quite enough as she settled for silver in 2:07.47.
She overhauled American Alex Walsh, who finished third in 2:07.66.
It was another disappointment for McIntosh in a meet she opened with a runner-up finish to Lani Pallister in the 200m freestyle. She bounced back with a victory in the 400m medley but misjudged her preliminary swim in the 400m free to miss the championship final.
Japan's Tomoyuki Matsushita completed a men's medley double with a 200m victory in 1:56.02.