The city’s top cop was a first responder before he was a grand marshal at the St. Patrick’s Day Parade Wednesday morning.

For the second time in two weeks, Police Commissioner Ray Kelly turned into a emergency worker, helping a woman hit by a bicyclist on the Upper East Side.

Kelly was on his way from a breakfast at Gracie Mansion to Mass at St. Patrick’s Cathedral around 8:30 a.m. when he saw a woman lying unconscious and bleeding from the head in the crosswalk at 84th Street and Fifth Avenue, said NYPD spokesman Paul Browne.

Kelly’s driver pulled over and he got out of his SUV to offer help.

“The police commissioner used her scarf as a compress to stop the bleeding,” Browne said. “While they assisted her, another detective called an ambulance.”

The woman was taken to New York Presbyterian Hospital/Weill Cornell Medical Center and was in stable condition yesterday with what was believed to be a fractured skull, said Browne.

The bicyclist who allegedly hit her, 24-year-old Jose Segarra, of Manhattan, stayed at the scene after the accident and was issued summonses for improper brakes, no reflectors and no lights.

On March 2, Kelly came to the aide of a woman near City Hall who had sprained her ankle and fallen in the street.

Wednesday's incident caused Kelly to show up late for Mass. During the service, Archbishop Timothy Dolan joked that Kelly was late because he was caught speeding, Browne said.

“It was a little embarrassing for someone who grew up Catholic on the West Side to be late for Mass,” Browne said.

advertisement | advertise on newsday

Kelly, however, made it to the parade on time.