The victim said the alleged assault took place when he got into his car in the Pak'nSave car park on Moorhouse Ave, chrislynchmedia.com reported.
He said a man approached from behind, opened his car door and punched him "for no reason".
The victim posted about the incident on social media and warned others to beware.
"I’m ok now. It was a bit scary, and it could happen to anyone.
"Just a note to self: Lock doors when you hop in your car.
"You shouldn’t have to, but there’s a lot of bad stuff happening," he wrote.
The man reported the incident to police.
"I was in shock, so I drove straight to the police station."
A police spokesperson told Chris Lynch Media they received a report of an assault on Moorhouse Ave on Tuesday.
"Enquiries were ongoing," the spokesperson said.
