Fans at Britney Spears' show in New Jersey on Saturday night (06Aug11) got more than they bargained for - fellow pop icon Lady Gaga was in the crowd.
The Toxic hitmaker is currently wowing with her Femme Fatale tour, and she hit Atlantic City over the weekend.
Atlantic City concert-goers were treated to two A-listers for the price of one - they went wild after Britney Spears pointed out her pop peer in the audience.
She told devotees, "I have a very special guest tonight... Lady Gaga is here."
Sitting in the VIP section in front of the stage, Lady Gaga stood up and waved to the cheering crowd, before dancing to Britney Spears' set and downing drinks.
Lady Gaga even stole the spotlight away from her host during a performance break - fans chanted her name and several flocked to the Poker Face singer for autographs.