A thug randomly sucker-punched a 47-year-old man — breaking his jaw — in what cops describe as a “possible knockout game” in the Bronx, disturbing surveillance video shows. 

The victim was walking on East 176th Street near Walton Avenue in Mount Hope just before 1:30 a.m. Jan. 20 when four strangers passed him in the opposite direction, police said. 

Video shows one of the men suddenly slugging the victim in the side of the face, knocking him to the ground — without saying a word.

The assault may have been part of a “knockout game,” cops said, referring to the sick spree of assaults that terrorized New Yorkers a few years ago.

The victim was taken to BronxCare Health System in stable condition, police said. 

The men fled after the incident and remain at large, cops said.