A guy previously busted for randomly slashing a stranger is the suspected Brooklyn serial attacker who fatally stabbed an 83-year-old man — after the victim may have won the lottery, cops and pals said Sunday.

Suspect Joevani Vale, 26, allegedly randomly first slugged a woman, slashed another female stranger and then followed and ambushed elderly Ramon Cintron — all in less than one horrific hour in Saturday’s Boerum Hill crime spree, cops said.

Police are now hunting for Vale.

“I love that old man like my grandfather,” Victor Santiago, the manager of Papa Firo Grocery in Boerum Hill, told The Post of Cintron on Sunday. “He comes every day at 5 [p.m.] and hangs out and plays the Lotto and the scratch-off. He does favors for everyone.

“He’s like a grandfather to the neighborhood,” Santiago said.

Two neighbors added to The Post on Sunday that Cintron scored while playing his daily numbers minutes before he was killed. It was unclear how much money the victim may have won.

Vale, who has at least three prior arrests, including for slashing a stranger in Brooklyn in September 2020, was identified in the slaying from surveillance cameras in the area, according to police.

Vale and Cintron were neighbors — they both lived in the Wyckoff Gardens public-housing complex.

Vale’s alleged violent spree began around 1 p.m., when he allegedly randomly slugged a 47-year-old woman at the intersection of Pacific Street and Third Avenue, police sources said.

Less than a half-hour later, he allegedly randomly slashed another woman, 31, in her leg in front of 134 Nevins St. before running off, cops said.

Shortly after 2 p.m., cops then found Cintron stabbed to death in the elevator on the 19th floor of Wyckoff Houses — just steps from his apartment, according to police.

The elderly victim had slash wounds to his neck and right arm and was pronounced dead at the scene.

A neighbor who said Cintron was affectionately nicknamed “Flaco” — Spanish for “Skinny” — said he knows both Vale and his victim.

“Flaco, everybody loved him,” the neighbor said. “He had a lot of heart.

“He goes over to that grocery store, Papa Firo, every day and plays the number, and yesterday he was going to collect on a winner,” the friend said. “And he followed him.

“I stay away from him,” the neighbor said of Vale.

Additional reporting by Steve Janoski