The 72-year-old responded, “I will do it again,” which caused the other to reply, “You’re a jerk.”
That's when things got physical and the older man struck the other man on the right side of his head, knocking off his hat and glasses, according to The State newspaper.
Greenville police said there are inconsistencies between the two men’s accounts of what happened.
The older man admitted to the altercation, but said the victim was "in his face" and balling up his fist, The State reported.
Investigators plan to review surveillance tape and are seeking any additional footage of the incident.
No arrests have been made.