A longstanding feud between two elderly men turned bloody Thursday when one repeatedly stabbed the other outside a Brooklyn pharmacy.

The fight between the two balding men erupted outside Pitkin Pharmacy in East New York about 3:30 p.m.

One neighbor described the stabber – a local who’d sweep the sidewalk outside area businesses – as a “good guy” who finally snapped after a history of being victimized by the other man.

“The victim was always after the assailant for something or another,” said the neighbor, who witnessed the aftermath of the attack. “I saw him beating the assailant with a chain just a couple weeks ago. With somebody beating him all the time, I guess he could only take so much.”

The attacker stabbed him in the torso and shoulders, witnesses said.

People gathered around the spectacle as emergency crews arrived.

The victim, shirtless and dripping with blood, appeared dazed as paramedics applied bandages.

The stabber, his orange t-shirt lifted and exposing his pot belly, stared menacingly at the victim as cops cuffed him.

Both men were taken to Brookdale Hospital. The assailant was then taken to the 75th police precinct, where he was facing charges Thursday evening.