The victim suffered a broken jaw, and the suspect fled the scene.
It happened around 5:40 a.m. Monday inside a bodega on Webster Avenue in Woodlawn Heights.
Authorities say the two became involved in a verbal dispute that turned physical, and the punch caused the elderly man to fall and hit his head.
The suspect fled the scene in a white Dodge van with New Jersey plates.
Police say he was in his mid-to-late 40s and wearing a gray hooded sweatshirt.
The victim was treated at Montefiore North Hospital for a broken jaw and brain swelling.
The investigation is ongoing.
Anyone with information is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782). The public can also submit their tips by logging onto the CrimeStoppers website at NYPDCRIMESTOPPERS.COM, on Twitter @NYPDTips.
All calls are kept strictly confidential.
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