A fiend in the Bronx ran up to an 81-year-old man who was reading a newspaper on a sidewalk and kicked him in the back of the head in an unprovoked attack, police said.

The suspect set upon the elderly man on Jerome Avenue near North Street in University Heights soon before 9 a.m. on Thursday, cops said.

Video of the attack shows him sprint up to the 81-year-old, who had his head buried in print news, and land a single kick with his right foot.

He then walked off, heading toward North Street, police said.

“It appears to be completely unprovoked,” a police source said.

The victim was rushed to Bronxcare Health System for injuries to his shoulder and wrist, cops said.

A suspect was arrested Friday night.