Summer McIntosh of Canada led all the way in winning the 400m individual medley at the Pan Pacific Championships on Thursday night, bouncing back after a runner-up finish in the 200 freestyle.

Australia led all but 150 meters of the women’s 4x200 freestyle relay, with the team of Inez Miller, Lani Pallister, Hannah Casey and Milla Jansen winning in 7min 42.40sec to lower the country’s championship mark of 7:44.12 set at the 2018 Pan Pacs.

Katie Ledecky swam the anchor leg for the US, but couldn’t overhaul Jansen although she got within a body length in the closing meters. Erin Gemmell, Anna Peplowski, Rylee Erisman and Ledecky took silver in 7:43.10, also going under the old championship mark.

“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.”

McIntosh helped Canada earn the relay bronze.

The US team of Luke Hobson, Aaron Shackell, Patrick Sammon and Gabriel Jett won the men’s 4 x 200 free relay in a championship record of 6:59.37. The Americans led the entire race, with Jett’s explosive turn off the final wall helping him hold off a charging Sam Short of Australia on the anchor leg.

“I just kind of poured everything on,” Jett said. “I swim with my eyes closed, so I didn’t know where I was.”

McIntosh briefly dipped under her own world-record pace early in the 400 IM. McIntosh finished in a championship record time of 4min 28.01sec after qualifying second-quickest for the eight-woman final at the outdoor pool.

McIntosh was disappointed with her time in the 200 free after losing to Pallister of Australia on opening night of the four-day international meet.

“Just trying to forget about it,” McIntosh said.

Jenna Forrester of Australia was second in 4min 31.50sec. Agostina Hein, an 18-year-old from Argentina, took bronze after coming into the final with the fastest time in preliminaries.

Meg Harris of Australia surprised herself with a victory in the women’s 100 freestyle from lane six. She touched in 52.60sec, beating American Gretchen Walsh, who was second in 52.78 after being 0.01sec under world-record pace at the turn. Olivia Wunsch of Australia was third.

American Simone Manuel, the 2016 Olympic champion, finished fourth.

The US went 1-2 in the men’s 100. Jack Alexy won in 47.14, lowering his championship-record time of 47.40 from the preliminaries. Teammate Patrick Sammon was second at 47.62. Guilherme Caribe of Brazil was third.

American McKenzie Siroky won the 100 breaststroke for her first international medal. She outdueled Tang Qianting of China down the stretch to touch first in 1min 5.32sec. Tang was second in 1min 5.46sec.

The US swept the 50 backstroke events.

Quintin McCarty won the men’s race in 24.51sec, lowering the championship record set by Isaac Cooper of Australia in the prelims. Cooper took silver.

Katharine Berkoff won the women’s race in a career-best 26.90sec, bettering her championship mark set in the prelims. Teammate Regan Smith was second in 27.14.

American Van Mathias earned his third medal of the meet, winning the 100 breaststroke in 58.02sec, lowering his championship record from the prelims. He took silver in the 50 butterfly and gold in the world record-setting 4x100 mixed medley relay Wednesday.

The men’s 400 IM was won by Tomoyuki Matsushita of Japan in 4:06.75. His time erased 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 US, I’m going to get gold again,” a smiling Matsushita said through a translator.

American Carson Foster was second.