Michigan police are investigating an incident at a local McDonald's last week that saw a staff member knockout an apparently unruly customer with a single blow, according to an MLive report.

Footage of the fight, which happened early last Thursday morning in East Lansing, made its way to YouTube and shows an unidentified McDonald's employee walking towards a man entering the fast food joint and delivering a powerful haymaker, knocking him flat on the ground.

Don't let the 10-second context-less clip fool you, though, the patron had it coming, according to a witness who spoke with MLive.

Local student Kevin Lange said the drunk customer acted belligerently, spat on the front counter and even threw a “Caution: Wet Floor” sign at employees.

Despite being asked to leave directly by the employee who went on to knock his lights out, as well as by the staffer's coworkers, the man reportedly made his way back into the eatery only to be greeted with a blow to the face.

"He definitely instigated it," Lange told MLive, referring to the customer. "But, it got taken too far. He didn't have to get punched, he could have got pushed out and told not to come back."