An NYPD lieutenant who was working at a Manhattan vehicle checkpoint on Saturday morning suffered a head injury after he was struck by a hit-and-run driver’s side mirror and knocked to the pavement, cops said.

The officer was at the vehicle safety checkpoint near Ninth Avenue and W. 207th St. in Inwood, just off the University Heights Bridge, around 3:40 a.m. when a black Dodge Durango swiped him before fleeing north into the Bronx, police said.

“We had a vehicle stopped at the location and the other vehicle was coming in the other direction,” a police spokesman said. “He gets hit with the mirror and falls to the ground and hits his head.”

The officer was taken to a local hospital in stable condition and was expected to survive, the spokesman said.

Cops were looking for the driver. It wasn’t clear why the other vehicle had been stopped or what the purpose of the checkpoint was.