Summer McIntosh of Canada delivered a commanding performance in the 400-meter individual medley at the Pan Pacific Championships on Thursday night, leading wire-to-wire to claim the title in a championship-record time of 4:28.01. The victory came just a day after the 19-year-old fell short in the 200 freestyle, finishing second to Australia's Lani Pallister. McIntosh did not hide her disappointment then, but she quickly refocused. "Just trying to forget about it," she said of the 200 free result. In the 400 IM, she built a substantial lead early, even briefly dipping under her own world-record pace before settling into a controlled rhythm. Jenna Forrester of Australia took silver in 4:31.50, while Argentina's 18-year-old Agostina Hein, who entered the final with the fastest preliminary time, earned bronze. McIntosh's teammate helped Canada secure a bronze in the women's 4x200 freestyle relay, but the spotlight was on Australia's dominant relay victory. The quartet of Inez Miller, Lani Pallister, Hannah Casey, and Milla Jansen clocked 7:42.40, slashing more than a second off the previous championship mark of 7:44.12 set in 2018. The U.S. team of Erin Gemmell, Anna Peplowski, Rylee Erisman, and Katie Ledecky finished second in 7:43.10, also dipping under the old record. Ledecky, swimming the anchor leg, nearly chased down Jansen in the final meters but came up short. "I've kind of struggled with the 200 individually from a flat start over the last couple years, but I always know I'll have something in me for the relay and I'll pull out a good split," Ledecky said. "I love swimming that anchor leg." In the men's 4x200 freestyle relay, the U.S. team of Luke Hobson, Aaron Shackell, Patrick Sammon, and Gabriel Jett led from start to finish, winning in a championship-record 6:59.37. Jett's explosive turn off the final wall helped him hold off a charging Sam Short of Australia. "I just kind of poured everything on," Jett said. "I swim with my eyes closed, so I didn't know where I was." The individual events produced several standout performances. Meg Harris of Australia stunned the field in the women's 100 freestyle, winning from Lane 6 in 52.60 seconds. American Gretchen Walsh, who was 0.01 seconds under world-record pace at the turn, settled for silver in 52.78, with Olivia Wunsch of Australia taking bronze. Simone Manuel, the 2016 Olympic champion, finished fourth. The U.S. swept the men's 100 freestyle podium, with Jack Alexy winning in 47.14, lowering his own championship record from the preliminaries. Teammate Patrick Sammon took silver in 47.62, and Guilherme Caribe of Brazil earned bronze. American McKenzie Siroky captured her first international medal in the women's 100 breaststroke, outdueling China's Tang Qianting down the stretch to touch first in 1:05.32. Tang was second in 1:05.46. In the 50 backstroke, the U.S. swept both events. Quintin McCarty won the men's race in 24.51, breaking the championship record set by Australia's Isaac Cooper in the prelims, who took silver. Katharine Berkoff won the women's race in a career-best 26.90, also improving her own championship mark, with teammate Regan Smith second in 27.14. American Van Mathias earned his third medal of the meet by winning the 100 breaststroke in 58.02, lowering his championship record from the prelims. He previously won silver in the 50 butterfly and gold in the world record-setting 4x100 mixed medley relay. The men's 400 IM saw Japan's Tomoyuki Matsushita win in 4:06.75, erasing American Ryan Lochte's championship mark of 4:07.59 set at the 2010 Pan Pacs, also in Irvine. "Next time I come back to the U.S. I'm going to get gold again," a smiling Matsushita said through a translator. American Carson Foster took silver.