A feisty 87-year-old man who was beaten up and robbed in Patchogue chased down the suspect, leading to an arrest.

John McMullen said he had just cashed his Social Security check Saturday at a North Fork Bank on East Main Street when a man hit him on the head as he walked to his car. The robber ran off with McMullen's money.

"When I got hit and pushed into that bush, I knew that I was in for a scrap," McMullen said. "He picked on the wrong person."

The retired Suffolk police officer's instincts kicked in and he ran after the suspect.

"I'm shouting 'Stop him, stop him! He robbed me!'" McMullen said.

Raphael Echeverri, 69, heard the commotion from inside Hough and Guidice Realty and joined the pursuit. The two seniors chased the robber for five blocks.

The men saw the suspect run into the Maple Tree Apartments on Maple Avenue. They called police, who surrounded the complex and busted 33-year-old Murray Martin.

The homeless man was arraigned Sunday in Central Islip.

McMullen said he plans to visit Echeverri to thank him in person for his help.