Indianapolis - Olympic stars Missy Franklin and Ryan Lochte shared the spotlight on Wednesday night, both claiming a pair of titles at the US swimming championships and World Championships trials.
Franklin's night began with a win in the women's 200m freestyle at the Indiana University Natatorium.
Ahead by a body length at the halfway mark, she touched the wall in one minute 55.56 seconds followed by Katie Ledecky in 1:57.63, Shannon Vreeland in 1:58.13 and Jordan Mattern in 1:58.27.
The win qualified Franklin - the winner of four gold medals and one bronze at the 2012 London Olympics - for the 200m freestyle at the World Championships in Barcelona, from July 28-August 4.
She also made the American 4x200m freestyle relay team, along with Ledecky - the winner of Tuesday's 800m freestyle event - Vreeland and Mattern.
Less than 90 minutes later, the recent high school graduate won the women's 200m backstroke in 2:05.68, the world's fastest time this year and an American open record as the best-ever performance in the US.
Franklin maintained a lead throughout to finish ahead of Elizabeth Pelton, whose 2:06.29 clocking was the world's second-fastest of 2013.
"That last fifty hurt so much," she said. "I'm ecstatic with the 2:05. But I'm definitely hurting now."
With three days to go at nationals, Franklin is eligible for five events at Worlds. Her first-place finish in Tuesday's 100m freestyle earned her a berth in that event as well as a spot the American 4x100m relay squad.
Lochte, the winner of five Olympic medals in London (two gold, two silver, one bronze), won the men's 200m freestyle and came back an hour-and-a-half later to finish first in the 200m backstroke.
Swimming in lane two in the 200m freestyle, Lochte led at the first turn and was never headed.
He finished in 1:45.97 ahead of Conor Dwyer, Matt McLean and Charlie Houchin. The quartet will comprise the US men's 4x100m relay team at Worlds.
In Lochte's second event of the night, he outdueled 2012 Olympic champion Tyler Clary in the 200m backstroke. Lochte won in 1:55.16 with Clary the runner-up in 1:55.58.
"I knew just from the lack of training this year that I had to go out fast," said Lochte. "I knew I was going to die either way, so I might as well just go out fast and hope for the best. I don't want to go through that pain again. That double was hard."
Tuesday night, Lochte made the US 4x100m relay team with a fourth-place finish in the men's 200m freestyle. He's now eligible for four events (200m free, 200m back, 4x100m and 4x200m freestyle relays) in Barcelona.
Kevin Cordes brought the crowd to its feet in the men's 200m breaststroke. Cordes, 19, was on world-record pace at the halfway mark. He finished short of the world mark (2:07.01 by Japan's Akihiro Yamaguchi in 2012), but settled for the year's top performance with a time of 2:08.34.
Breeja Larson stroked into the lead in the women's 200m breaststroke on the final turn and won in 2:23.44.
In major surprise, Allison Schmitt failed to qualify for the women's 200m freestyle final. Schmitt, the American record holder in the event, was the 2012 Olympic champion. She also swam on the gold medal-winning US 4x200m freestyle relay team in London.
The 50m butterfly was contested for the first time at the national meet. Christine Magnuson won the women's title in 26.08 while the men's race went to Eugene Godsoe in 23.29.
Results of finals on Wednesday on the second day of the US Swimming Championships and world championship trials:
200m freestyle: 1. Ryan Lochte 1:45.97, 2. Conor Dwyer 1:46.25, 3. Matt McLean 1:46.78
200m breaststroke: 1. Kevin Cordes 2:08.34, 2. BJ Johnson 2:10.09, 3. Nic Fink 2:10.97
200m backstroke: 1. Ryan Lochte 1:55.16, 2. Tyler Clary 1:55.58, 3. Ryan Murphy 1:56.37
50m butterfly: 1. Eugene Godsoe 23.29, 2. Matt Grevers 23.50, 3. Tim Phillips 23.69
200m freestyle: 1. Missy Franklin 1:55.56, 2. Katie Ledecky 1:57.63, 3. Shannon Vreeland 1:58.13
200m breaststroke: 1. Breeja Larson 2:23.44, 2. Micah Lawrence 2:24.69, 3. Laura Sogar 2:24.86
200m backstroke: 1. Missy Franklin 2:05.68O, 2. Elizabeth Pelton 2:06.29, 3. Elizabeth Beisel 2:07.64
50m butterfly: 1. Chris Magnuson 26.08, 2. Kendyl Stewart 26.19, 3. Claire Donahue 26.23