A bicyclist was struggling to survive after he struck a pedestrian, flew over his handlebars and hit the pavement in Manhattan Sunday morning, cops said.

The biker was riding north on First Avenue when he collided with a 21-year-old man who was crossing the street at East 111th Street in East Harlem around 12:30 a.m., according to police.

The man, whose identity wasn’t immediately released, was taken to Harlem Hospital with serious head injuries.

It wasn’t clear if he was wearing a helmet, police said.

The pedestrian was uninjured.