Kicking off what was an action-packed weekend in Tinseltown, Rebecca Black made a surprise guest appearance at the Katy Perry concert in Los Angeles on Friday night (August 6).
The YouTube sensation was brought onstage with the pair treating the sold-out crowd to a rendition of Rebecca's hit song "Friday".
Upon show's end, an ecstatic Miss Black tweeted, "Thank you SO much @katyperry for having me on stage tonight! What an UNBELIEVABLE experience.(: Definitely won't forget this one!!"
Meanwhile, Rebecca's fun-filled weekend continued with an appearance at the 2011 Teen Choice Awards - where she was named as Choice Web Star winner.
Of the Teen Choice triumph, Black happily wrote, "Can't believe I won a TEEN CHOICE AWARD!!!! This is crazy. Thanks to all that voted!"
Photo Credit: SplashNewsOnline.com