An irate customer bashed a Manhattan deli employee with a “wet floor” sign after the worker told him the lotto machine was shut down for the night, new video shows. 

The suspect was inside a deli on Canal Street near Orchard Street in Chinatown around 2:15 a.m. Sunday when the employee turned him away, cops said Thursday night. 

Video shows the would-be gambler heading for the door but then turning back, picking up the yellow sign and bashing the worker over the head with it. 

The victim suffered pain and swelling to his head and hand. 

The suspect took off in a black BMW and is still on the loose, according to cops.