You also had to wonder whether the 4-foot-11, 78-pound leader's 9:32 p.m. start — last among the 20 women — was past her bedtime.

Whatever difficulties she experienced, Nagasu, just 14, coped well enough to become the second youngest U.S. women's champion ever, taking first place with a good-enough performance at the Xcel Energy Center.

Fifteen-year-old Rachael Flatt was second and Ashley Wagner, 16, third. University of Delaware freshman Kimberly Meissner, the defending champion, was a disappointing seventh.

"I'm very excited and speechless for words," Nagasu said.

The new champion, who is 34 days older than Tara Lipinski was when she took the 1997 title, is too young to represent the United States at the 2008 World Championships in Gotheborg, Sweden, this March. So is Flatt.

As a result, the U.S. team could consist of Wagner, fifth-place Katrina Hacker, and sixth-place Bebe Liang, though it's possible the committee could decide to send Meissner, who won the World Championship in 2006.

To be eligible, competitors must have turned 15 by July 1, 2007.

That didn't seem to bother Nagasu, who plans to compete in the World Junior Championships, an event in which she finished second to Caroline Zhang in 2007.

"I just want to rack up the experience for when I get to go to worlds," she said.

Despite her sleeplessness, Nagasu had built a comfortable lead with a brilliant short program that resulted in the highest point total ever for a woman in the U.S. Championships — 70.23.

That left her with nearly an eight-point advantage over her closest competitor, Wagner.

She fell once early, on a double-axel, then skated well enough to compile a total of 190.41, an advantage of less than two points over Flatt's 188.72. Wagner totaled 188.56. Neither had a major mistake in the four-minute program.

"When I fell on that double-axel, it was like a kick in the butt," Nagasu said. "After that, I attacked."

The results were devastating to Meissner, who fell three times and fought off tears as the NBC cameras zoomed in on her face while she waited for what would be a score of 157.56.

"I'm so bummed," said Meissner, who tumbled to the ice on a triple-flip and two triple-lutzes. "I just didn't have a good competition. I'm very upset."

Entering Saturday night's skate, she trailed three younger teens — Nagasu, Wagner and Flatt — all of whom were making their senior U.S. Championships debuts.

Trailing Nagasu by more than 12 points and in fourth place, Meissner, 18, tried to overcome the leaders with a challenging free-skate program, one that fell apart early.

Veteran observers suggested hers might have been one the worst performances by a defending champion. Michelle Kwan fell twice when Lipinski upset her in 1997.

Perhaps in deference to the ankle she injured earlier this winter, the program did not include a triple-axel, the jump that lifted her onto the national scene as a 14-year-old.

Asked whether she planned any major changes on her team, Meissner said she would need time to weigh her options.

Nagasu, just as she did at the U.S. Junior Championships a year ago, surprised Zhang, another 14-year-old and a budding rival, who had arrived here with more hype than her fellow Californian.

Nagasu had received a good-luck fax from her idol, Japan's Mao Asada.

Ice dance. In what was the least surprising result here, Tanith Belbin and Ben Agosto easily won their fifth consecutive U.S. ice-dancing championship last night.

It was the kind of skate "that could win them the world championship," NBC commentator Tracy Wilson said.

Their training mates, Meryl Davis and Charlie White, were second.

Horsham's Brent Bommentre, an Eagles fan who skates out of the Philadelphia Skating Club, and his partner, Kim Navarro, were third.

Bommentre and Navarro continued their steady climb in the standings. They finished fifth in 2006 and fourth a year ago.

"We just focused on skating as well as we could here," said Bommentre, 26. "We're very happy."

With their finish, Bommentre and Navarro earned a trip to the world championships for the first time.