Credit: Mark Davis/WireImage

Beatles fans got a surprise Saturday night when none other than Dave Grohl appeared onstage at a Paul McCartney show.

The Foo Fighters rocker grabbed a guitar at McCartney’s show in London at the O2 Arena, and together, the pair performed “I Saw Her Standing There.” This isn’t the first time the duo have played the Beatles’ classic together: with Grohl on drums, McCartney sang “I Saw Her Standing There” at the 2009 Grammys.

Grohl’s cameo wasn’t the only big moment from the show. McCartney also performed one song live for the first time ever: “Temporary Secretary,” which was first released on McCartney II in 1980.