Yikes! Justin Bieber was the target of a brutally overeager partier in a Toronto nightclub. The 'Believe' singer was attacked by a stranger in the wee hours of this morning (Aug. 31).

TMZ nabbed photos of the incident.

Bieber left his cozy VIP area to mix and mingle with the commoners, which turned out to be a mistake. A random partier decided it would be cool to attempt to tackle the boy wonder and grab onto the shirt on his back.

Security rushed in and Bieber defended himself with a "flurry of kicks." Guards threw the jerk out of the club and police were never called -- though really, we wouldn't blame the Biebs for wanting this creep prosecuted to the fullest extent of the law. What he did was beyond not cool.

Understandably, Bieber and his crew left shortly after. Considering the scumbag tried grabbing onto Biebs' shirt, it's no wonder he wanders around topless all the time!