Surveillance video was released on Monday that shows a man, identified by investigators as 29-year-old Barry Baker of Georgetown, Delaware, punching the victim in the face.
It happened outside the 7-Eleven at 200 South High Street in West Chester around 2:30 a.m. back on May 10.
As the video begins, the victim is seen pulling up in a white SUV just as the suspect walks out of the store.
That's when a man in a yellow sweatshirt, identified by investigators as Baker, appears to mock the victim after he goes inside.
A few minutes later, the victim walks out of the store and the suspect apparently mocks him again.
The suspect then follows the victim into the parking lot and punches the victim in the face without warning.
The victim stumbles backward over the hood of his SUV as the man identified as Baker walks away.
The 22-year-old victim composes himself, gets into his vehicle and drives away. Police say he then contacted police.
"This defendant is a bully. Every decent citizen should be outraged by the defendant's conduct. The victim is to be commended for keeping his cool and notifying the police," D.A. Tom Hogan said.
Baker was charged with simple assault and related crimes. He is free on $25,000 bail.
Police earlier said Baker had a last known address of Coatesville, Pa., but said on Tuesday that Baker provided an address in Delaware at his arraignment.