The two-time Olympian came within a whisker of setting a world record in the 100 backstroke last night, winning twice in about an hour at the U.S. National Championships.

His time of 53.01 seconds was the second-fastest ever, just three-hundreths of a second off Aaron Peirsol's mark set in March at the world championships. Perhaps a more ominous message to the swimming world is this: Phelps thinks he can go faster.

"How much?" coach Bob Bowman asked. "A lot. A lot faster because he's done next to no preparation for that race specifically."

It seems the only thing that can stop America's golden boy from winning is himself.

Phelps set a meet record in the 200 freestyle with a time of 1:44.98, then regrouped and still had enough energy to swim what Bowman called his best closing 50 ever in the 100 back.

The two wins were his third and fourth of the week and put him within one victory of becoming the first American man to win five titles in back-to-back summer nationals. He had also won five events in 2003 and 2006. No other American man has even done it once.

But it won't happen Saturday because of the deal Phelps cut with Bowman on Friday morning.

"Our deal was that if I broke 45 (in the free) and 54 (in the back), then I could have a sleep in tomorrow," Phelps said. "It's good to have a sleep-in day because I've not had one in a while."

Pulling out of Saturday's 200 individual medley means Phelps will have to wait at least two more years to add that line to his impeccable resume.

He did match another one of his previous records Friday by winning the freestyle — giving him three victories in different strokes. He's the only man to do that, too.

But Phelps was challenged, at least.

He had to fend off the hard-charging Peter Vanderkaay, his teammate with Club Wolverine, to take the 200 free. Vanderkaay was second in 1:45.45 — both under the previous meet record.

In the 100 back, Phelps watched Indiana University's Ben Hesen go out quickly, turning in a 25.78, a sub-world record split.

This time, Phelps rallied. He hit the wall hard, pushed and got past Hesen, who struggled in the last 50. By the time David Cromwell started to close on Phelps the only remaining question was whether Phelps would break the record.

Cromwell was second in 53.82, Hesen third at 54.40.

"I saw them going out, and I didn't want them to get too far ahead," Phelps said. "I did look at the scoreboard, and I wanted to hit the wall hard and then I saw myself going past them."

Phelps wasn't the only one turning heads in Indianapolis.

Brendan Hansen, who complained Tuesday night about the air quality inside the natatorium, easily won the 100 breaststroke Friday.

The world-record holder in the event dominated the race, finishing in 59.59 — the sixth fastest time in history. Hansen owns five of those marks. Mark Gangloff was second in 1:00.43, and Hansen acknowledged that the times were better because the swimmers could breathe more easily.

"I was coughing all night the other night," Hansen said. "But I was watching from the pool deck the last couple of nights and it was better. Once we got that (message) out, they got it taken care of real fast."

The other big event was the third head-to-head matchup this week between Kate Ziegler and Katie Hoff in the 200 free.

Ziegler won the first two races — the 400 and 800 free. Hoff dominated this one. She took the lead at 100 meters and pulled away from both Ziegler and Dana Vollmer to win by nearly a full second. Vollmer and Hoff were roommates at the 2004 Olympics and at this year's world championships.

Hoff set a meet record, 1:57.57, while Vollmer finished in 1:58.53. Ziegler was third at 1:58.66.

"The 200 is a pretty good event for me," Hoff said. "I'm getting better in the 400 and 800, but that's definitely my best race."

Rebecca Soni also made a splash. The Southern Cal student, who had surgery to correct a rapid heartbeat last summer, won the 100 breast in 1:07.06. Olympian Megan Jendrick was second in 1:07.19, and Tara Kirk was third at 1:07.35.

Hayley McGregory won the women's 100 back in 1:00.93. Leila Vaziri was second in 1:01.03.

As usual, Phelps won over the crowd with his special performance, even if he wasn't at his best.