Law enforcement sources tell TMZ ... Brown was busted late Friday night after officers pulled him over for driving without a license plate. We're told once cops went in for a closer look, they found that Brown smelled of alcohol -- so they administered a field sobriety test ... and he didn't perform well.
According to sources, Brown almost dodged the DUI bullet. We're told cops stopped him in front of his house, with his pregnant girlfriend in the car.
Brown was booked at 12:38 AM at the famous Hollywood station on suspicion of DUI. He posted the $15,000 bail and was released at 7:42 AM on Saturday.