Authorities say the suspect sat next to the 68-year-old victim on an uptown No. 6 train around 8 p.m. Wednesday and kissed her on the forehead.
When the victim rebuffed her advances, police say the suspect grabbed her hair, punched her in the head and face and fled.
The victim suffered a bruise on her forehead.
The suspect is described as a black female in her 40s, approximately 5-foot-11 and weighing 150 pounds, with black hair and brown eyes.
Anyone with information regarding this incident is asked to call Crime Stoppers at 1-800-577-TIPS (8477).