The NYPD has released a grainy surveillance photo of the mugger, which police hope leads to an arrest.
The incident happened over the weekend, around 11 p.m. Saturday, on 58th Street between 11th and 10th avenues, after victim Andrew Billington and his girlfriend left a concert.
The 37-year-old, who was reportedly in town to train for the New York Marathon, had just left the Terminal Club when he was approached from behind and struck over the head with a brick apparently covered in a cloth. After Billington hit the ground, police say he was struck again in the face.
The suspect proceeded to reach into Billington's pockets, but did not remove any property.
All the while, Billington's girlfriend was screaming, terrified.
Billington was transported to Bellevue Hospital and is listed in stable condition.
The suspect is described as a light-skinned Hispanic or black male, 20 to 25 years old, approximately 6 feet tall and weighing 160 to 170 pounds, with a moustache.
The suspect was observed wearing a red hooded sweatshirt, blue waist-length jacket, black jeans, black and white sneakers and a black baseball hat.
Police are hoping to locate additional surveillance video of the incident or suspect.
Anyone with information in regards to this incident is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS.