Pop superstar Justin Bieber was ambushed on stage by a topless fan during a concert in Rio de Janeiro, Brazil on Sunday (03Nov13).

The Boyfriend hitmaker, who is in South America as part of his Believe World Tour, was left stunned when a young man jumped on to the stage to grab him from behind in a bid to personally greet the star.

In a video posted on YouTube.com, the youth is seen rushing on to the stage while Bieber is performing a routine with his back-up dancers, and he puts his arms around the star before being escorted off stage by security officers.

It follows an incident in Sao Paulo on Saturday (02Nov13) when the teen heartthrob stormed off stage after a member of the crowd fired a plastic bottle at him.