Brendan Hansen gave himself one more shot at an elusive individual Olympic gold medal as he won the men's 100m breaststroke at the US Olympic swimming trials.
Hansen, 30, secured his London Games berth with a victory in 59.68sec, with Eric Shanteau second in 1:00.15.
The final was one of three on the second night of the trials, which also featured Ryan Lochte's narrow victory over Michael Phelps in their 200m freestyle semi-final.
Dana Vollmer laid the ghost of 2008 with a victory in the women's 100m butterfly.
Vollmer was under world record pace at the halfway stage, but she was more than happy to take the victory in 56.50sec and a return trip the Olympics after missing out on Beijing.
Claire Donahue snagged the second London berth with her runner-up finish in 57.57.
Allison Schmitt, who trains with Phelps under coach Bob Bowman, was equally convincing in winning the 400m freestyle in 4:02.84, with Chloe Sutton securing the second Games berth in 4:04.18.
Hansen had retired from swimming after the Beijing Games, where as in Athens he fell short of individual gold despite going into the Olympics as one of the world's top breaststrokers.
"I'm really proud of myself for saying I was going to come back and then coming back," said Hansen, who found his competitive fire re-lit when he began taking part in recreational triathlons.
Shanteau, who made the US team for Beijing and competed there despite being diagnosed that summer with testicular cancer, had rallied on the final lap to finish second.
"It's nice to have it all come together when it counts the most," said Shanteau, who reckons himself more of a 200m man.
"I had no idea where I was," he said. "I told myself I wasn't going to look, just get my head down at the finish."
Vollmer won the 100m fly world title at Shanghai last year, but in returning to Omaha she returned to the scene of bitter disappointment in 2008, when she finished fifth in the 100m fly and seventh in the 200m free and failed to make the Beijing team -- four years after she earned relay gold as a teenager in Athens.
"I don't think I could be disappointed right now," Vollmer said. "Going into the race, I wanted it to be a smart race. I wanted to get on the team first and foremost, so I didn't want to take it out super hard.
"I set myself up well and got on the team. I'm really relieved that I did that, and I'm so excited to get to do it in London."
Natalie Coughlin finished seventh in the 100m fly final, missing her first chance to make a third Olymic team.
Coughlin, an 11-time Olympic medalist, then kept her hopes of earning a third straight 100m backstroke gold alive as she advanced to the final -- but she was only seventh-fastest out of the semi-finals as rising star Missy Franklin led a bevy of talented teenagers into the championship race.
"I love how I feel right now -- strong and powerful," said Franklin, an ebullient 17-year-old who is tipped for Olympic stardom after a breakout performance at last year's World Championships.
"It's so awesome to feel this way and to be able to come here and do what I came to do," added Franklin, who led the way into the final with a time of 59.06sec.
Rachel Bootsma, 18, was second-fastest in 59.10, with 17-year-old Olivia Smoliga and 18-year-old Elizabeth Pelton the third- and fourth-quickest.