WATCH: Paul McCartney, Bruce Springsteen Perform Together

Paul McCartney surprised fans at his concert at New York's Madison Square Garden on Friday night by bringing out Bruce Springsteen during the encore.

The two rocked out the Beatles’ hit “I Saw Her Standing There” – and the fans went wild.

"The last time we played together was in London's Hyde Park and they pulled the plug," McCartney told the crowd, referring to a 2012 performance that went past the park's noise curfew.

“Rockin' out with The Boss – Sounded so good we had to do it twice!,” McCartney tweeted after the show.

Watch the performance below: