Jimmy Fallon crashes Paul McCartney's Vancouver concert

Fans at last night'ssold-out Paul McCartney concert at Vancouver's Rogers Arena were treated to an array of surprises, including an unexpected performance by Jimmy Fallon.

• Paul McCartney in Vancouver for 'One on One' tour

The Tonight Show host joined Sir Paul on stage during the encore to sing and rock out to I Saw Her Standing There.

But not beforetaking off his Canucks hat and wishing people happy4/20.

"When you were playing yesterday, the guy infront of me legalized it for at least three minutes, so I want to say congratulations to that guy," said Fallon.

Fallonrocked out hard andeven broke out his best human worm dance moves, prompting McCartney to joke about his 'low energy' after the song.

Fallon was not the only special guest at Sir Paul's One on One tour concert the Delta Police Pipe Band also took to the stage.