Police were looking on Sunday for a suspect who followed a 54-year-old woman home to her Upper East Side apartment, then beat and robbed her.

The suspect, described as about 40 to 45 years old and about 5-feet-4-inches, followed the woman to her East 67th Street apartment at about 11 p.m. on Friday and demanded her bag, police said.

Surveillance video of the incident then shows him punching her so hard her head appears to slam back against the wall.

The woman suffered a laceration to her left eye and bruising to her face. She was treated at New York Presbyterian Hospital, police said.