A new viral video shows an elderly Bronx man being knocked out, and robbed inside his apartment building.

Police say that the attacker sucker punched a 63-year-old male resident in the head. The man was knockout and robbed. The attacker managed to steal cash out of his pockets.

It happened Friday around 8 p.m. in Fordham Heights, with the victim found beaten and bloodied by his 18-year-old daughter lying on the floor inside the building.

Police say the suspect followed the man, who speaks Spanish and didn't want to be identified, into his building before punching him.

The victim, a married father of four, suffered a concussion and fractured eye socked. The suspect stole $40 in cash and a bag of groceries.

Here's the video: