SAN DIEGO - Britney Spears took the stage late Tuesday at the House of Blues, making what is believed to be her first public concert appearance in nearly three years.

Starting the five-song set with her debut single "Baby One More Time," Spears was back in top form. The one-time teen pop queen appeared onstage in boots, a sparkly pink bra top and a short white skirt with her belly ring out.

The drama of the past few months appeared to be behind her.

Her only words came as she was leaving. "Thanks everyone for coming," she told the packed club, where people paid upward of $125 a ticket.

Tuesday's appearance — in which Spears wore a long brown wig — was shrouded in mystery. The club marquee made no mention of Spears, announcing only the performance of "The M&Ms." Word, however, quickly spread on the Internet and fans posted well wishes for her comeback performance.

"The M&Ms" had two other concerts scheduled at House of Blues venues in Southern California — one in Anaheim on Wednesday and the other Thursday in West Hollywood — according to the club's Web site.

Earlier this year, the 25-year-old successfully completed a stint at a luxury Malibu drug rehabilitation treatment facility after a bout of headline-generating behavior that included a February stop at a San Fernando Valley hair salon to shave her own head in front of television news cameras.

Spears filed for divorce in November from aspiring rapper Kevin Federline, just two months after giving birth to their second child, Jayden James. The pair also have an older son, Sean Preston, now 20 months.

The two reached a divorce settlement in March.

Her last concert tour ended in summer 2004. Earlier this year, Spears told fans of her plans for a hot career comeback.

"I look forward to coming back this year bigger and better than ever," Spears wrote in a January posting on her Web site, also noting she's "been far from perfect."

The singer also drew disapproval from celeb gawkers for her late-night outings with party girls Paris Hilton and Lindsay Lohan. Spears noted that in those nights out — which included flashing her apparent lack of underwear to the paparazzi — she may have taken her "new found freedom a little too far."