Irvine :Michael Phelps held on for a "painful" victory in the 200m butterfly at the Pan Pacific Swimming Championships on Wednesday, holding off Nick D'Arcy with the fastest time in the world this year.
"That was painful," said the 14-time Olympic gold medallist, who has been battling all season after a lengthy break from training.
Phelps led at every turn and won in 1min 54.11sec, 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, who was second in 1:54.73. Japan's Takeshi Matsuda was third in 1:54.81.
Cesar Cielo, the 50m freestyle Olympic gold medallist, departed from his signature sprint freestyle events to lead a Brazilian one-two in the 50m butterfly.
Cielo won in a sizzling 23.03sec, with Nicholas Santos second in 23.33 and South African veteran Roland Schoeman third in 23.39.
"It's a wonderful surprise," Cielo said after notching the fastest time of the year in the event. "I'm not really a butterflyer, but anything that's a 50 I find a way to go fast. Tonight I found a way to find a way to go really fast."
Australian Geoff Huegill, making his return to international competition after retiring in the wake of the 2004 Olympics, was fourth.
The meeting is one of the two biggest international championships of the year, along with the recently completed European championships. Along with the four charter PanPac nations of the United States, Canada, Australia and Japan swimmers from a host of other non-European countries are taking part.
For the US swimmers, results will help determine places on next year's World Championship team, while for Australian swimmers some places in the Commonweath Games at New Delhi in October are up for grabs.
Ryan Lochte won the 200m 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.
Park, the 2008 Olympic 400m free gold medallist and 200m free silver medallist, briefly seized the lead at the halfway point, but Lochte surged back for the victory.
World record-holder Aaron Peirsol made the most of a second chance in the 100m backstroke, winning in 53.31 after Lochte's decision to scratch gave him a slot in the final.
"I wanted to make the most of the opportunity," said Peirsol, who had one of the top eight times in the heats but was bumped to the consolation final as the third-fastest American. Only two swimmers from each nation can compete in each championship final.
Peirsol delivered a steady first 50m and took control at the turn. He powered to the win over Japan's Junya Koga (53.63), with Australian Ashley Delaney third in 53.67 and Japan's Ryosuke Irie settling for fourth in 53.71.
Reigning world champion Marieke Guehrer won the women's 50m butterfly in 25.99sec - the same time her fellow Australian Yolane Kukla posted in winning the consolation final.
Australian Emily Seebohm took silver in 26.08sec, enough to add the event to her Commonwealth Games programme.
Seebohm then won a hard-fought victory in the 100m backstroke, clocking 59.45 to edge Japan's Aya Terakawa (59.59) with American Natalie Coughlin third in 59.70.
Jessicah Schipper gave Australia another narrow victory in the 200m butterfly, clocking 2:06.90 to edge Americans Teresa Crippen (2:06.93) and Kathleen Hersey.
Allison Schmitt won the women's 200m freestyle in 1:56.10, leading fellow American and training partner Morgan Scroggy (1:57.13) with Australian Blair Evans third in 1:57.27.
US women finished one-two in the 800m free as well, with Kate Zeigler winning in 8:21.59 ahead of Chloe Sutton (8:24.51).
Ryan Cochrane gave Canada their first gold of the championships with a fine 1,500m freestyle victory in 14:49.47. American Chad La Tourette was second in 14:54.48 and China's Zhang Lin third in 14:58.90.