Columbus Short -- who plays gladiator Harrison Wright on "Scandal" -- was involved in a bar fight in which the other guy ended up in the hospital and cops are now conducting a criminal investigation.
Law enforcement sources tell TMZ ... Short was at Gabe's Bar and Grill in L.A. on March 15 at around 10:45 PM celebrating a couple's engagement ... when he started arguing at the bar with another partygoer.
We're told the other guy pissed Short off by making a comment along the lines of, "You might be richer than me but I get my girls to buy me everything I want including your wife."
An eyewitness tells TMZ Columbus then came up from behind and sucker punched the guy. The eyewitness says the man's nose was broken and he was rendered unconscious for several minutes.
We're told Columbus quickly left the bar.
An ambulance came and took the 37-year-old man to a nearby hospital.
Cops are now investigating a criminal battery.
It's not the first time Columbus used his fists to make a point. In March, 2010 ... Columbus was playing basketball at an L.A. Fitness gym when he got into an argument with another player and socked the guy in the face, knocking several teeth out.
We reached out to Columbus ... so far no comment.