A confrontation between a bicyclist and a pedestrian at a busy midtown intersection turned violent when the cyclist, who appeared to be a food deliveryman, wrapped his bike chain around his hand and punched the pedestrian in the head, police say.

It happened in Hell's Kitchen just before 9 p.m. on July 26, when the cyclist and the 22-year-old pedestrian nearly collided at the corner of West 44th Street and Ninth Avenue, police said. The two got into an argument, and the pedestrian tried to walk away.

That's when the man on the bike took off his bike chain, wrapped it around his hand and punched the victim in the back of the head, according to police. EMS responded and took the victim to Bellevue Hospital in critical condition.

The suspect is described as being about 5-feet-7 to 5-feet-8, last seen on a blue 10-speed bike, wearing a black backpack with the word RELAY printed on it. Relay is a courier platform connecting delivery workers with restaurants in New York City.

Anyone with information is asked to contact Crime Stoppers at 800-577-TIPS or nypdcrimestoppers.com.