COLLEGE PARK, Md. - If there is a chink in Michael Phelps' armor, no one this side of Ian Crocker has been able to find it.

Phelps, 18, of the North Baltimore Aquatic Club won his fourth event of the week and set the American record in the 400m free Friday night at the ConocoPhillips National Championships.

It was the third-fastest time in the world this year, but Phelps said that between this meet and the World Championships, all this racing is finally starting to take its toll.

"I'm really starting to feel it now," Phelps said. "I think we've reached our limits here, and the tank's riding on very, very empty right now.

"With 150 to go, I saw everyone's arms waving and cheering me on, and that really helped me along. I owe that (finish) to the crowd, because they really got me home."

Another swimmer having quite a week is Kalyn Keller. Keller, 18, of Trojan Swim Club held off a charge by Canada's Brittany Reimer and teammate Kaitlin Sandeno to win her second event of the week in the 400m free. Her time was 4:10.68.

"I was very excited about it," Keller said. "I knew I was in a heat with a lot of experienced and talented swimmers, and I knew if I wanted to win, I was going to have to go out there and show them who's boss in the third 100. It might have cost me a little bit at the end, but that's what I had to do.

"Like I said after the 800 (free), next year is going to be interesting, and this is a good starting place for next year."

"Next year" began tonight for Ed Moses, 23, of Curl-Burke who won the 100m breast with a time of 1:01.11 for his 11th national title.

"I was obviously a little disappointed with World Championships, and I wasn't planning on coming here, but there was nothing I could get but information by coming here and swimming tonight," Moses said. "I look at this as the start of the season for me, not the end, and I'm really pleased with the direction I'm going. I'm going to take this on a positive note."

Another familiar name took the top spot in the women's 100m breast, as Olympic gold medalist Megan Quann, 19, of the South Sound Titans won with a time of 1:08.90.

"I can definitely be faster than that, but it was fun to come here and race against some tough competition," Quann said. "I wanted to be a 1:07. That didn't happen this time, but hopefully next time."

Winning her first national title Friday night was 2003 National Junior Team member Lauren Rogers, 16, of Terrapins, who finished the 100m back with a time of 1:02.50.

"It was pretty shocking," Rogers said. "I wasn't expecting to do it, actually. I wasn't even aiming for a first. I was just going for a best time.

"So to come in first and drop nine-tenths off my best time is pretty exciting for me."

In other events, Randall Bal, 22, of Stanford won the men's 100m back with a time of 54.63, the ninth fastest time in the world this year. Bal finished more than a second ahead of teammate and former world record-holder Jeff Rouse, who's aiming for Athens after a six-year retirement. Rouse was second in 55.64.

"I would have liked to have gone faster, but I always say that," Rouse said. "I need to get a little stronger in my legs and do a lot more speed work, but that was progress."

Emily Goetsch of North Baltimore won her first national title in the 100m fly with a time of 59.87, while South African Eugene Botes won the men's 100m fly with a time of 53.20. It was an early birthday present for Goetsch, who turns 18 tomorrow.

"I thought it was possible," Goetsch said, "but I didn't have a very good 200 fly the other night, so I just wanted to go out and have fun tonight and not be so serious."