Ed Moses looked strong at the midway point of his preliminary heat in the 200-meter breaststroke Saturday at the U.S. Olympic swimming trials, leading the eight-man field by a healthy margin and turning in the fastest split time of any swimmer in five heats.

But over the final 50 meters, Moses, who swam at Virginia and is from Burke, was nearly caught from behind. He touched the wall first, .02 second ahead of Gary Marshall. Yet the performance showed just how difficult it will be for Moses -- who won a silver medal in the 100 breaststroke and gold in the medley relay in 2000 at Sydney -- to make the 2004 Olympics.

He was fifth fastest in Saturday night's semifinals; only the top two swimmers in Sunday night's final will make the Olympic team.

"There's pressure, but I've been in this position many a time," Moses said. "It really doesn't have anything to do with anybody. You try to swim the race you've been training for."

Yet Moses, 24, said that has been difficult for him this week. He was sixth in the 100 breaststroke on Thursday, nearly three seconds behind winner Brendan Hansen, who set a world record of 59.3 seconds. During the heats, Moses complained he might be battling food poisoning. Saturday, he said he was taking medicine because his asthma was acting up.

"It's a little painful," he said. "But I'm not going to give up. . . . The [asthma attacks] are few, and this is just a very, very bad time for one like this, just because I wasn't feeling that bad until things started to get heated up."

Hansen, meantime, seems poised to push for another record in the event. He was fastest in the morning prelims by more than two seconds and in the evening semifinals by more than three seconds.

"I'm on a roll," Hansen said after the morning session. "After the 100, it was kind of hard to stay focused and not get too excited about what had just happened. But [U.S. Coach Eddie Reese, who coached Hansen at the University of Texas] has been really adamant about making sure I warm down, making sure I'm eating right, making sure everything's going well."

Moses, meantime, must be concerned only with himself.

"I think he's on fire right now, and swimming really well," Moses said. "I'm not on the team yet, and the only way I can do that is swim my own race."

Women's Showdown

The outgoing and incoming giants of the women's team -- Jenny Thompson and Natalie Coughlin, respectively -- swim the prelims and semifinals of the 100 freestyle Sunday. The top four finishers in Monday's finals will make up the 400 freestyle relay team, an event in which Thompson won gold in 1992, 1996 and 2000. . . .

Sunday is the second of two live NBC broadcasts from the trials. Along with the men's 200 breaststroke and 100 freestyle, viewers will see the women's 200 butterfly final, featuring 2000 gold medalist Misty Hyman.