A 40-year-old man was fatally shot in the back during a clash on a Brooklyn street corner early Saturday, police said.

Cops responding to a report of shots fired found victim Anthony Lancaster sprawled on the ground near the corner of Clarkson Ave. and E. 52nd St., a quiet residential area in East Flatbush, around 2:15 a.m., police said.

Lancaster had been shot twice in the back and once in the head, and he died at the scene, cops said.

The victim lived in Brooklyn about a mile from where he was shot, they said.

No arrests have been made, and a suspected motive for the killing was not disclosed.

Detectives were scouring the area for surveillance footage to help piece the violent incident together.