A man who was selling illegal MetroCard swipes at a Harlem subway station was fatally stabbed Wednesday night by the father of a woman he ripped off, police said.

The 53-year-old victim was standing near the turnstiles of the 116th Street station when a woman agreed to buy a swipe just before 9 p.m.

But instead of allowing her to pass, he snatched a dollar from her hand and refused to swipe her through, police said.

The woman left the station, but soon returned with her father, identified as 48-year-old Julio Velazquez, who then chased the man above ground and knifed him in the back near 116th Street and Lenox Avenue, cops said.

The wounded man then fled back into the station and hopped onto a downtown 2 train but collapsed one stop later at the Central Park North – 110th Street station.

Straphangers called 911 from that station and paramedics rushed the victim to St. Luke’s Hospital, but he succumbed to his injuries soon after, according to the FDNY.

The victim’s name is being withheld pending family notification.

Velazquez was still at large. Cops were searching for the weapon Wednesday night.