Video: Miley Cyrus on-stage with Justin Bieber for 3D movie

Aug. 31, 2010 - New York, New York, U.S. - MILEY CYRUS, JUSTIN BIEBER.Justin Bieber ''My World'' Tour - concert being filmed for a documentary about Bieber. Madison Square Garden, New York City 08-31-2010. 2010.Justin Bieber ''My World'' Tour - Madison Square Garden.K66233JBB. © Red Carpet Pictures

Miley Cyrus teamed up with Justin Bieber for a duet last night – and it was all for his 3D movie.

The pair performed Bieber’s track Overboard at the gig at Madison Square Garden, New York, to a delighted crowd.

16-year-old Justin also sang with Usher, Sean Kingston, Ludacris and Boyz II Men during the concert.

Speaking of Bieber’s 3D movie, director John Chu told MTV: “[It’s] a movie for his fans, a movie for people who don’t know him, we’re gonna tell the underdog story of where he came from. Because it’s a really fascinating story and it has a lot to do with our sort of digital lifestyle now.”

“He was able to do what corporations try to do now when they use YouTube and they don’t even know what to do with it yet. It’s a pretty cool story for our time.”