Authorities say the incident happened on Sunday outside the Stater Brothers on Bear Valley Road and Navajo Road at 7:49 p.m. The 79-year-old victim was unloading his cart when he "accidentally bumped into the vehicle next to him with his leg," police said in a press release.
The suspect jumped out of his gray Hyundai, shouting at the victim and accusing him of scratching his vehicle. The suspect then punched the victim in the face twice, causing the man to fall to the ground.
Deputies were called to the scene, but the assailant had left before they arrived. The victim was treated for injuries to his face, head and neck, authorities said.
The suspect was described as a white male adult, about 6 feet tall and 200 pounds, last seen wearing a gray T-shirt and gray baseball cap. The vehicle was described only as a newer gray four-door Hyundai sedan.
Anyone with information is urged to call the Apple Valley Police Department at (760) 240-7400, or (800) 78-CRIME.