Fresh Prince of Bel-Air Star Breaks Up Brawl

Sources tell TMZ, the fight broke out between two employees at "In the Cuts" in Hollywood -- after a disagreement over which should be turned up louder ... the TV or the radio.

It gets physical pretty quickly -- but Alfonso doesn't miss a beat ... reaching into the frame with his badass gold-watched arm to pull the two guys apart, saying, "Let go, let go."