Kate Douglass clocked an American record of 2min 19.30sec to win the women's 200m breaststroke on Saturday as the Pro Swim series meeting in Knoxville, Tennessee, concluded.
Douglass, who won 200m medley gold at last year's World Championships in Fukuoka, erased the previous American record of 2:19.59 set by Rebecca Soni in winning Olympic gold in 2012.
Douglass sliced 1.92sec off her personal best as she became the fourth-fastest performer ever in the event.
Russian Evgeniia Chikunova tops that list with the world record of 2:17.55 set last April.
Canada's Summer McIntosh grabbed her third win of the week, overhauling American Alex Walsh on the closing freestyle leg to win the 200m individual medley in 2:07.16.
Walsh had seized the lead from McIntosh on the penultimate breaststroke leg, but couldn't hold off the Canadian teenager, who also won the 200m butterfly and 200m freestyle this week.
Katie Ledecky, eying a fourth straight Olympic 800m freestyle gold in Paris this year, closed out the week with a dominant victory in the event.
The US freestyle great, who won the 1,500m and 400m free in Knoxville, clocked 8:14.97 to win the 800m by more than 12 seconds.
Paige Madden was second in a personal best of 8:27.44, holding off Jillian Cox who took third in 8:28.00.
Austrian Felix Auboeck capped his strong week with a victory in the men's 800m free in 7:51.96. Belgian Lucas Henveaux was second in a personal best of 7:55.64.
Auboeck notched his third win of the week after victories in the 200m and 400m freestyle. He was second in the 1,500m free.