In the latest battle of the snow-packed streets, a 66-year-old South Boston man who paid to have a spot shoveled for his car confronted a neighbor who parked there — and was punched in the face and left unconscious in a pool of his own blood, police said.

Several witnesses told the Herald there was no space saver in the Mercer Street spot, and said the elderly man followed the suspect, grabbing his arm repeatedly as he walked away.

Police arrested Juan Beltran-­Rivera, 32, who lives around the corner from the alleged victim, and charged him with assault and battery on a person 65 or older. The victim was taken to Tufts Medical Center with “serious facial cuts” as well as his “left eye being completely swollen shut.”

“He stated that he arrived home and found his neighbor (suspect) beginning to park in a parking space that he had earlier in the day had paid to be shoveled for his temporary use,” police wrote. “The victim stated that he approached his neighbor and explained the situation to him, but the neighbor refused to (sic) his vehicle from the cleanly shoveled spot.”

“Officers observed a large pool of blood 20 feet from the intersection where the victim landed,” police said.

The elderly man told police Beltran-Rivera struck without warning.

Beltran-Rivera told police he felt intimidated by the man during the argument and “things got out of hand.” Efforts to reach Beltran-Rivera and the victim for comment were unsuccessful.

A neighbor who declined to give her name said she saw the attack from her window. She said both the men are “nice guys.” The suspect pulled into the spot, and had no sooner parked then the older man drove up and blocked him in with his car, an­nouncing it was his spot. She said when he was confronted, the suspect walked away.

“The old dude followed the young gentleman and kept grabbing his arm,” the woman said. “The young gentleman kept shaking him off, shaking him off. He did this three, four times.”