TIMES SQUARE — Cops have arrested a homeless man for allegedly sucker-punching a straphanger in the Times Square subway station and stealing his cell phone, the NYPD announced.

Leonard Johnson, 31, was charged with robbery, police said.

Johnson allegedly attacked his victim, a 35-year-old man, early Monday just after midnight, cops reported.

Video released by the NYPD shows the victim standing just inside the station's turnstiles at West 42nd Street and Seventh Avenue, when his attacker approaches, briefly speaks with him, then suddenly turns and punches him in the face, knocking him to the ground.

Johnson, who police say is the suspect in the video, allegedly stripped the victim of his cell phone, then fled on foot toward the northbound 1 Train platform.

The 35-year-old man declined medical attention, police say.