The NYPD released a sketch of the man they are looking for.
The 15-year-old victim was walking at the corner of Horace Harding Expressway South Service Road and 155th Street on Wednesday night when the suspect brandished a knife and demanded her cellphone, police say.
She refused and attempted to run away. The man slashed her left leg before fleeing without any property.
The victim sustained a laceration and was removed to New York Presbyterian Hospital in stable condition.
The NYPD describes the suspect as a white male in his forties, approximately 5'9" tall, 170 lbs, blue eyes, long brown curly hair, and last seen wearing a dark baseball hat and blue shorts.
Anyone with information is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).