Two motorcyclists were killed and one was critically injured in three smash-ups across the city overnight, cops said.

The first collision happened just before 11 p.m. in Harlem, when a 42-year-old male motorcyclist was fatally struck by a hit-and-run motorist on the southbound Henry Hudson Parkway, near West 145th Street, authorities said. 

The other driver continued south on the parkway, cops said. 

The gravely injured motorcyclist was taken to Harlem Hospital, where he was pronounced dead. 

About an hour later, a 19-year-old male motorcyclist was killed in Maspeth, Queens, cops said. 

The teen motorcyclist collided with a Nissan, driven by a 58-year-old man, at 64th Street and 58th Road minutes before midnight, police said. 

He was rushed to Elmhurst Hospital Center, where he died of his injuries. 

The Nissan driver stayed at the scene, and no arrests have been made.

Early Friday morning, a 28-year-old male motorcyclist got into another crash at the intersection of Bruckner Boulevard and Waterbury Avenue in the Country Club section of the Bronx, police said. 

He lost control and slammed into a wall around 4:15 a.m., cops said. 

The man was rushed to Jacobi Medical Center, where he was listed in critical condition. 

There were no other vehicles involved and no criminality was suspected.