SAN JOSE, Calif. — Agnes Zawadzki sure knows how to shake things up.

SAN JOSE, Calif. — Agnes Zawadzki sure knows how to shake things up.

The U.S. junior champ only two years ago, Zawadzki outskated not one, not two, but three former winners Thursday night to claim the short program at the U.S. Figure Skating Championships. One of the few women to skate cleanly, her sultry routine to a blues medley earned her 66.24 points and put her three points ahead of defending champion Alissa Czisny going into the free skate Saturday. Ashley Wagner was third.

Mirai Nagasu, the 2008 U.S. champ, was fifth after botching her opening jump. Rachael Flatt, the 2010 winner, was way down in ninth after a lackluster performance in front of an enthusiastic hometown crowd.

"I'm really excited," Zawadzki said, still grinning 15 minutes after she got off the ice. "Everything's finally clicked."

Earlier Thursday, Mary Beth Marley and Rockne Brubaker took a big lead in the pairs competition, winning the short program by more than four points. Marley and Brubaker, who already has two U.S. senior titles with former partner Keauna McLaughlin, scored 65.80 points with their delightfully peppy "Singing in the Rain" program.

Amanda Evora and Mark Ladwig, runners-up last year, were second again (61.27), followed by Caydee Denney and John Coughlin (60.88), winners of the last two pairs titles with different partners. The free skate is Saturday.