Irvine - Katie Ledecky clocked the second-fastest time in the world this year to win the 200m freestyle at the US swimming championships on Thursday, holding off the challenge of 2012 Olympic champion Allison Schmitt.
Ledecky touched in 1:54.60 - second only to her own 1:54.56 in June this year - to add the 200m title to the 800m freestyle crown she claimed on Wednesday.
Ledecky led from start to finish, but the 28-year-old Schmitt, who returned to competition in April for the first time since the Rio Olympics, clung to her hip all the way to finish second in 1:55.82 and Ledecky looked as pleased with Schmitt's finish as her own.
She was already looking forward to teaming with Schmitt in the 4x200m freestyle relay at the Pan Pacific Championships in Tokyo in August.
"I knew she was having a great swim the whole race, just having her right there the whole time right next to me," Ledecky said of Schmitt, a three-time Olympian who stepped away from the sport after the Rio Olympics and only resumed training last September.
"She's just the most likeable person and such a great friend and such an asset to Team USA. It's going to be great to have her in Tokyo."
Gabby Deloof was third in 1:56.55 and Leah Smith fourth in 1:56.93, all securing berths for the Pan Pacs, which with this week's meet will serve as the qualifier for the 2019 world championships in South Korea - curtain raiser to the 2020 Olympics in Tokyo.
Schmitt, who has used her experience struggling with depression to become an outspoken advocate for mental health care, was buoyed by some supportive pre-race texts from her old teammate Michael Phelps.
"I got paragraphs from Michael," said Schmitt, who added she was "ecstatic" to find herself headed to Pan Pacs after arriving in Irvine unsure just what to expect from herself.
Josh Prenot, a Rio silver medallist who failed to qualify for last year's world championships, made a statement in the 200m breaststroke, winning with the fastest time in the world this year of 2:07.28.
"It feels good to be swimming breaststroke that way again," said Prenot, who notched his fastest time since 2016. "I definitely lost the flow for a while there. It's been a process to find it over these last few months. I had a shoulder injury that kept me to just a kickboard for a month. I think it was really good just to have that hard reset and relearn how to swim the stroke."
Andrew Wilson was second in 2:08.71, edging Will Licon by one one-hundredth of a second.
Andrew Seliskar turned it on in the second half to win the men's 200m freestyle in 1:45.70 - improving on the personal best of 1:45.77 he posted in the heats to install himself as third-fastest in the world this year.
Blake Pieroni, winner of the 100m freestyle on Wednesday, was second in 1:45.93 with Connor Dwyer third in 1:46.08.
Townley Haas, leader at the 100m mark, was fourth in 1:46.15.
Micah Sumrall won the women's 200m breaststroke in dominant fashion, posting the fourth-fastest time in the world this year of 2:22.06.
Sumrall, on the comeback trail after failing to make the Rio Games, touched 1.26 ahead of Bethany Galat in a field that saw Olympic 100m breaststroke champion Lilly King settle for fifth.
A scintillating women's 200m backstroke saw 16-year-old Regan Smith and two-time Olympic medalist Kathleen Baker finish in a dead heat for first place in 2:06.43.
The time was just outside Baker's bronze medal-winning time of last year's world championships in Budapest - and a world junior record for Smith.
Ryan Murphy, whose three gold medals in Rio included the 100m and 200m backstroke, powered through the final 50 to win the 200m back in 1:54.15 - second-fastest of 2018.
Jacob Pebley held on to finish second in 1:55.68.