7:35 AM PT -- Witnesses tell TMZ ... Chris' Greg Yuna chain was snatched off. It's a chain where all the links come apart, so it fell apart on the street when the culprit snatched it. The suspect ran away and the chain was recovered by Chris.
Witnesses also say police took photos of Chris' injuries, which include a deep cut on his nose.
'SNL' alum Chris Redd was in no laughing mood in NYC Wednesday night ... the comedian got slugged in the face by some random dude and was rushed to the hospital, but, thankfully, he's gonna be OK!!!
Law enforcement sources tell TMZ ... Chris drove up to the Comedy Cellar in Greenwich Village around 9:40 PM and got out of a vehicle when all hell broke loose.
We're told a man, apparently wearing a security guard uniform, ran up to Chris and clocked him in the face, bloodying his nose.
Cops were on patrol in the area and quickly responded to the scene, but the assailant had already run off. Police don't know the motive for the alleged assault.
People gathered around to assist Chris -- as you see in video obtained by TMZ. Blood was on the sidewalk and several steps leading down to the Comedy Cellar. Chris was scheduled to perform there Wednesday night.
He was taken to Bellevue Hospital in Manhattan, where he was treated and released.