The men's 400 freestyle failed to produce a world record but was full of drama with Larsen Jensen winning in a time of 3:43.53 ahead of Peter Vanderkaay and Erik Vendt. The three swimmers were separated by just 0.39 seconds.
Brendan Hansen almost added another world record, posting the top qualifying effort of 59.24 in the 100 breaststroke semifinals. The time was the fastest this year and just off Hansen's own world record of 59.13.
Phelps, six-time Olympic gold medalist, had been scheduled to swim nine events over the eight days but withdrew from the 400 freestyle before the preliminaries on Sunday.
Michael Phelps (R) celebrates after he broke world record during the Men's 400m Individual Medley at the U.S. Olympic Swimming Trials in Omaha of the United States, June 29, 2008.(Xinhua Photo)
He is expected to swim only the 200 freestyle today (Shanghai time) after his name did not appear on the start list for the 100 backstroke preliminaries.
"Being able to start the meet the way I did helps me relax a little bit more," said Phelps, who will celebrate his 23rd birthday tomorrow.
"I didn't want to lose that race, I was pretty fired upcoming into the final. I just went out there and did whatever I could to get my hand on the wall first.
"You saw how emotional and excited I was after the race. I never really take one hand and thrash the water, I was pretty fired up."
(Agencies Via Shanghai Daily July 1, 2008)