Michael Phelps held on for a "painful" victory in the 200-meter butterfly at the Pan Pacific Swimming Championships Thursday, holding off Nick D'Arcy with the fastest time in the world this year.

Michael Phelps of the U.S. reacts after winning the men's 200m butterfly final at the Pan Pacific 2010 swimming championships in Irvine, California, August 18, 2010. [Xinhua/Reuters Photo]

"That was painful," said the 14- time Olympic gold medalist, who has been battling all season after a lengthy break from training.

Phelps led at every turn and won in 1 minute 54.11 seconds, but said he could feel rivals closing in the final meters.

"I felt a splash of water from the lane next to me, I was just thinking 'Please don't let me get run down,'" Phelps said. "The fitness level is just not there."

Even so, he had enough to hold off Australia's D'Arcy in 1:54.73. Japan's Takeshi Matsuda was third in 1:54.81.

Cesar Cielo, the 50-meter freestyle Olympic gold medalist, departed from his signature sprint freestyle events to lead a Brazilian one-two in the 50-meter butterfly. Cielo won in a sizzling 23.03 seconds, with Nicholas Santos second in 23.33 and South African veteran Roland Schoeman third in 23.39.

The meeting is one of the two biggest international championships of the year, along with the recently completed European championships.

Ryan Lochte won the 200-meter freestyle in a year's best time of 1:45.30, holding off the challenge of South Korean Park Tae-hwan, who was second in 1:46.27.

Aaron Peirsol won the 100-meter backstroke in 53.31 seconds.