A straphanger was shoved into the side of a moving train in Brooklyn during an unprovoked attack in the subway system this week, cops said.

The 36-year-old victim was waiting for a train on the platform of the 59th Street station in Sunset Park just after 6 p.m. Sunday when the suspect approached him and pushed him into the side of a northbound R train, according to police.  

The victim bounced off the train and fell back onto the platform. He never fell onto the tracks. 

The attacker didn’t say a word to the victim and fled the scene of the crime.

The victim, who suffered bleeding to the head, was taken to NYU Langone Hospital-Brooklyn in stable condition.

Surveillance footage shows the bearded suspect, who has a light complexion, wearing a dark-colored jacket, winter hat, and white-and-black sneakers.