Despite rumors indicating that pop star Justin Bieber was going to cancel an appearance last night at Australia’s Acer Arena due to a back injury, the star not only showed up—he came with a special superstar guest in tow.
According to MTV News, Bieber surprised concertgoers when he brought out Chris Brown to join him onstage. The duo performed the remix to Bieber's “Up.”
Earlier this week Biebs fueled speculation about the performance when he sent out a tweet hinting at the onstage collaboration. At that point whether Bieber would even perform by himself seemed in doubt, after reports that the singer might cancel the show. He quashed those rumors hours before taking the stage.
"I don't cancel ... In route to Sydney!! THE SHOW IS ON!! I don't let my fans down! LEGGO!! #myworldtour," he wrote on Twitter.
It just so happens that both stars are currently touring in Australia. Brown began his F.A.M.E. world tour Down Under on April 20, while Bieber is keeping a 10-date commitment for his My World tour. 

(Photos, from left: Erika Goldring / Retna Ltd., Mark Metcalfe/Getty Images)