Tags the guy pretty good although I'm not sure what warranted the punch...

 

 

During a show on April 30 in Aspen, Colo., a fan who was tossing money around in the crowd was pulled on stage by Pitbull. The guy then thought it would be a good idea to make it rain in Pit's face ... and was dead wrong.

Pitbull suddenly levels the guy -- repeat, LEVELS the guy -- with a devastating right hand, then follows it up with a Beckham-esque kick once the dude was on the ground.

...

http://www.tmz.com/2009/05/27/rapper-knocks-dude-out-doesnt-miss-a-beat/