Police nabbed the suspect minutes after the attack. View Full Caption Anton K. Nilsson/DNAinfo

EAST HARLEM — A would-be robber on parole for a previous robbery was thwarted by bystanders after beating a man unconscious, police said.

Wilson Cruz, 25, sucker-punched a 28-year-old man in the head, then knocked the victim down to the ground, where he fell unconscious, on June 3 around 9 p.m. near East 118th Street and 1st Avenue, according to police and prosecutors.

Cruz then tried to take the victim’s wallet and flee, but several onlookers stopped him, police said. After Cruz ran from the mob, police nabbed him less than a block away.

The victim was taken to a local hospital for treatment.

Cruz was also on parole for a previous robbery, police said. He was charged with second-degree robbery and second-degree assault for the June 3 attack, according to the criminal complaint.

He was held on $35,000 bail, according to court records.

A lawyer for Cruz could not be reached for comment.