A man was pummeled on a Bronx subway train last week when he got into a fight with another straphanger over a seat, authorities said.

The 58-year-old victim was riding a southbound 4 train around 6 a.m. March 7 when his attacker approached and began arguing with him.

While the man was still sitting, the suspect grabbed him and hurled him to the floor before punching him several times in the face and head and leaving him with a busted lip, cops said.

When the train arrived at the Mount Eden Avenue station, the victim ran off and called 911 while his attacker remained onboard.

The suspect was last seen wearing a black hoodie, blue jeans and a black baseball cap.