GREENSBORO, N.C. — No tricks, no potions. Just Mirai Nagasu being her usual enchanting self.

GREENSBORO, N.C. — No tricks, no potions. Just Mirai Nagasu being her usual enchanting self.

The 2008 champion edged out fellow previous winners Alissa Czisny and Rachael Flatt in the short program at the U.S. Figure Skating Championships on Thursday night with a beguiling routine to "Witches of Eastwick."

But with the margin between the three so small — just 1.03 points, to be exact— and only two spots on the world team available, Saturday night's free skate should be quite the show.

Nagasu scored 63.35 points while Czisny, the 2009 champ, had 62.50 points. Flatt, the defending champion, scored 62.32.

Nagasu was fourth at the Vancouver Olympics, and her lyrical style, expressiveness and charming personality made many think she was on the verge of becoming figure skating's next big star. But the 17-year-old doesn't have quite the confidence in herself others do, and those doubts tend to come out at the most inopportune times.

She led the world championships after the short program, but came apart in the free skate and dropped to seventh. A stress fracture that kept her off the ice for two months this summer got her down and made for a rough start of the year.

When her score was posted and Nagasu saw she was in first place, she beamed and flashed a double thumbs-up to the camera.

"A lot of people still expected a lot of me, even though I hadn't skated in a while," Nagasu said. "All the best skaters can step up their game, and I'm learning how to do that."