Chris Brown -- Up to His Neck in Half-Naked Girl

6/16/2011 4:00 AM PDT
Chris Brown squared off against a friend recently in a butt-filled battle of strength at a Miami pool -- playing everyone's favorite summer game ... the Chicken Fight ... with two VERY cheeky women.

No word on whether Chris won -- but when the dust settled ... we're told it was a real weight off the singer's shoulders.