Hawai'i swimmers Noa Sakamoto and John Flanagan fell short in their bids to represent the United States in the 2008 Olympic Games in Beijing, finishing fifth and eighth, respectively, at yesterday's USA Swimming 10K Open Water World Championship Trials at Miromar Lakes Beach and Golf Club in Fort Myers, Fla.

"It's very disappointing but I'm definitely very happy with my effort because I didn't leave anything out there," said Flanagan, 32. "And, I'm really proud of how Noa did. He had a great race."

Mark Warkentin won the highly competitive, physically bruising event in 1 hour, 57 minutes, 1.84 seconds. He and second-place finisher Chip Petersen automatically advance to the 2008 FINA Open Water World Championships April 29 to May 4 in Seville, Spain.

The top 10 finishers in that event automatically qualify for the Beijing Olympics.

Sakamoto, a 21-year Stanford University senior, finished in 1:57:19.57. Flanagan finished in 1:57:21.56.

Flanagan said the parity and competitiveness of the field made for a long and difficult morning.

"It was four-guys strong at the top and I was in the next group," he said. "It was an extremely slow pace back there and it was hard because there was a lot of contact as guys fought for (drafting) position. That aspect was very difficult."

Flanagan, who suffered cuts near his eye from being kicked in the pack, broke away several times and actually led the race at a couple of points, but the rest of the pack wasn't willing to let any one swimmer maintain a lead.

"They wouldn't let anyone go," Flanagan said. "But if you stayed back in the pack, you took a beating."

Course officials issued several warnings for the swimmers to separate from each other.

Flanagan was in the top four heading into the final 100 yards of the race but was overtaken in the mad scramble for the finish. In a bittersweet moment, Flanagan watched as Sakamoto, a fellow Punahou alumnus and training partner, swam past him.

"He went right by me in the last few meters," Flanagan said. "He really fought a good fight and I'm proud of him. He had a great day."

Sakamoto was on a flight back to California yesterday afternoon and could not be reached for comment.

The hard-fought race took its toll on many of the top swimmers. Fran Crippen, a pre-race favorite and Pan American Games gold medalist, placed ninth behind Flanagan.

"Everyone was so close that it was never clear who would win it," Flanagan said. "If we raced again tomorrow, it would probably still be the same top 10, but the order would be different."

The event marked the end of a stirring comeback attempt for Flanagan, whose nine-month pursuit of an Olympic bid took him around the globe.

"It's time to evaluate," he said. "It's been a long journey. All I've focused on was trying to make it to Beijing. It's definitely disappointing because of how much I put into it, but I'm thrilled to have been part of such a competitive race and I'm proud of what I was able to do.

Reach Michael Tsai at mtsai@honoluluadvertiser.com.