OMAHA, United States (AFP) - Superstar Michael Phelps got his bid to make a fifth Olympic team off to a smooth start on Tuesday with the top qualifying time in the 200m butterfly at the US swimming trials.
"I just wanted to swim," said the 18-time Olympic gold medallist, whose reduced program at this year's trials left him kicking his heels on the first two days of competition.
As usual, Phelps was his own worst critic after winning his heat 1min 56.68sec.
"Third turn was bad, lost all the momentum," Phelps said. "I felt like I didn't really use much legs, kind of dragged them along.
"So," he added, looking ahead to the evening's semi-finals, "something to build off of tonight."
Two days shy of his 31st birthday, Phelps is vying to become the first man to make a fifth US Olympic swimming team, and finish off his remarkable career with a last blaze of glory in Rio.
The 200m fly was the event in which a teenaged Phelps set his first world record, and his world mark of 1:51.51 - set at the tail end of the bodysuit era in 2009 - still stands.
Regaining the Olympic title he surrendered to Chad le Clos in London in an event he long considered his baby figures to be a strong motivator for Phelps in Rio, but he was taking things one step at a time.
"I'm happy to get the first (event) under way," said Phelps, whose time put him 22-hundredths of a second ahead of his nearest challenger, Pace Clark, going into the semis.
Katie Ledecky bounced back nicely the morning after her impressive triumph in the 400m freestyle, leading the 200m free heats in 1:55.60.
"It's a pretty tough race coming off last night," said the freestyle phenomenon, who has been inexorably expanding her dominance to include shorter races in addition to her world record events the 400m, 800m and 1,500m free.
"I've gained a lot of confidence, especially going 1:54 (in the 200m) a few times this year," she said. "I know what I need to do in that race."
Meanwhile, London Games darling Missy Franklin posted just the seventh-fastest time of the 200m free heats, three-seconds slower than Ledecky's.
Franklin was already facing an uphill battle to book a Rio berth in the 100m backstroke on Tuesday night, having qualified just seventh-fastest for the final in an event that she won in London.
"I was not happy with that at all," Franklin conceded, but said she hoped the challenge of swimming both the 100m back final and 200m free semi on Tuesday night.
"I think I do my best when I'm given a greater challenge," Franklin said.
Other finals on tap Tuesday include the men's 200m free and the men's 100m backstroke - in which David Plummer (52.12) and Ryan Murphy (52.28) notched the fastest times in the world this year to lead reigning Olympic champion Matt Grevers (52.64) into the final.