NFL's Justin Hunter -- Sucker Punched Victim ... Prosecutors Say

Tennessee Titans WR Justin Hunter fights like a bitch ... sucker punching a man outside a Virginia bar in a ferocious attack ... this according to prosecutors.

Hunter just appeared in court in Virginia Beach ... where his mother was inside the courtroom crying ... as Justin faced charges he assaulted a man at Sandbar Raw Bar on July 3rd.

Prosecutors say Hunter and his friends approached another group of guys they didn't know and began arguing ... and at some point during the argument, Hunter began throwing punches.

The victim, prosecutors say, fell to the ground ... and Hunter and his pals continued to beat and kick the man.

Officials say the man eventually got up and left the bar -- and was outside spitting up blood -- when Hunter got out of a Range Rover and sucker punched him while he was hunched over.

The victim claims he was hospitalized for 2 days -- with a broken jaw, cracked tooth ... and also had a tooth knocked out.