Singer Britney Spears has made her first appearance on stage since she left a rehabilitation clinic.
Spears' partying lifestyle has made headlines
The 25-year-old, who was photographed in February shaving her head in a hair salon, performed five songs at the House of Blues club in San Diego.
An unknown act called The M&M's had originally been billed to appear at the California venue.
As she left after performing for 20 minutes, the mother-of-two said: "Thanks everyone for coming."
After rumours that The M&Ms was a cover for Spears spread, tickets started to sell for far above their $35 (£17.56) face value.
The singer's arrival at the venue was greeted by a horde of photographers and excited fans.
The singer shaved her head in front of TV cameras
For the short set she wore a white miniskirt, a pink bra top and a brown wig.
"I think she worked the stage, her body looked great. So it was good to see her finally come back and prove us all wrong," a female fan told Los Angeles TV station KNBC.
Two other M&Ms concerts are scheduled for 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.
Spears has not released an album since 2003. After her 2004 marriage to aspiring rapper Kevin Federline she announced she would take some time off to "just chill".
After she parted from her husband last year she began a late-night lifestyle culminating in a spell in rehab.