According to People magazine, Spears performed yesterday for 14 minutes at the San Diego House of Blues. Security guards kept a close watch on the star during her appearance.
The starlet lip-synched her hits Baby One More Time and Toxic. The brief show featured several costume changes, dancers, special effects and smoke effects.
Last week, the singer cancelled her appearances at the Forty Deuce club in Hollywood.
Spears, 25, has not performed on stage since June of 2004, when she injured her knee.