Michael Phelps secured a fourth straight Olympic berth in the 200m butterfly, cruising to victory at the US trials in an event he has long dominated.
Phelps, who has held the world record in the 200m fly since he first broke it at the age of 15 in 2001, will have a chance at a third straight gold medal in the event at the London Games.
Trailing Davis Tarwater at the first two turns, Phelps on Thursday turned it on heading into the final turn and powered home to win by a body length in 1min 53.65sec.
"It's not a good enough time to win a gold medal, but I think I'm OK with it," Phelps said, although it was the fastest time posted so far this Olympic season.
Behind him, Tyler Clary won a furious race for second place -- and the other London Games berth on offer -- rallying to claim second in 1:55.12 ahead of Bobby Bollier and Tarwater.
Clary, who missed out on a trip to London as he finished third in the 400m medley behind Ryan Lochte and Phelps, pounded the water in celebration when he saw he was headed to the Olympics.
"It was amazing," Clary said. "I can't even put into words how the end of that race felt, not only the pain in the last 20 meters but just the complete and total turnaround.
"I'm on cloud nine right now," he said.
Phelps stayed on track to repeat the eight-race programme he swam in Beijing, where he won an unprecedented eight gold medals in one Games to take his tally of gold to 14.
Midway through the eight-day selection meeting he has qualified in the 400m medley, 200m freestyle and 200m fly, with the 100m fly and 200m medley still to come and three relay spots likely on the cards.
"That was the best my stroke's felt throughout the meet," said Phelps, who has stepped up his training after a post-Beijing lull.
"In all I'm pleased, but I think I need to go faster if I want to win that at the Olympics.
"I was just thinking about it today, this is my fourth Olympic Games in this event, so it's special to me ... I have a couple of weeks to perfect some things that I'm going to need if I want to end with a good one."
Allison Schmitt, who trains with Phelps and coach Bob Bowman at North Baltimore, added another race to her Olympic programme, winning the 200m freestyle in 1:54.40.
That's the fastest in the world this year, improving on the 1:54.66 posted by France's Camille Muffat.
"I didn't feel like I was on my (American) record pace, but I could hear the crowd. I was pretty excited before I even looked up and saw the time," said Schmitt, who won the 400m free earlier this week.
Teen sensation Missy Franklin, fifth at the first turn, surged to second to add the event to a London schedule that already includes the 100m backstroke.
In the day's other final, Caitlin Leverenz won the women's 200m individual medley in 2:10.22 to give herself a shot at a medley double in London. Ariana Kukors, who set the world record in the event in 2009, before high-tech bodysuits were banned, finished second to seize an Olympic berth.
Nathan Adrian led the way into the final of the men's 100m freestyle with a semi-final time of 48.33, which put him among the top 10 performers this year in the prestigious event.
Lochte, pursuing his own multi-medal programme in London, was equal fifth-fastest in the semis but scratched from Friday's final to focus on the 200m backstroke -- which he won in Beijing -- and the 200m medley -- which promises another showdown with Phelps.