Jessica Hardy added the 50 free title in 24.50 to her earlier 100 free win making her the American sprint queen of the 2012 US Trials. Kara Lynn Joyce was second in 24.73. It was the end of the road for 45-year old Dara Torres with her fourth-place finish in 24.82.
Hardy, coached in Los Angeles by David Salo, posted her personal best, improving on her prevous best of 24.55 from the semis.
Kara Lynn Joyce was off her best of 24.59 from 2008 but she got the better of Christine Mangusson, Tucson Ford, third with 24.78.
"Missing it by less than a tenth of a second is tough," Torres said. "Going to the Olympic trials against girls half my age, it's OK. I mean, I'm used to winning but that wasn't the goal here. The goal was trying to make it. I didn't quite do it."
Torres won 12 Olympic medals during her Olympic career, starting with relay gold in the 4x100m free in 1984 aged 17 in Los Angeles. Her Olympic years ended with silver 0.01sec behind Britta Steffen (GER) in the 50m free in Beijing four years ago after she came out of retirement for a second time. Since Beijing, she has undergone surgeries on her shoulder and knee.
"This is really over," Torres said. "That's it, I'm going to enjoy some time with my daughter, have a nice summer and cheer on the U.S. team. Obviously I was hoping to make the team. That was my goal and missing it by less than a tenth of a second is tough, but I don't think there's anything I could have changed."
Torres remembered her late coach, Michael Lohberg, who died in 2011 from a rare blood disorder. "I was very emotional before my swim," Torres said. "When I was putting my suit on with my trainer, Anne Tierney, we started crying because I started thinking about Michael. In July of 2010, he had said to me, 'Let's go for this.' I really wanted to finish the story that I started with him. I didn't make it but I know he would have been proud."
Hardy, 25, said: "I love racing Dara. I wish she could have made it this year, but swimming with her the past couple years has been really an awesome treat for sure."
On her own swims, she said: "Doing so well, winning two races here, I couldn't have predicted this in a million years," Hardy said. "I'm so happy and so grateful that this meet went as it did."