A video has been posted on Youtube capturing the moment when an employee of a McDonald's store in East Lansing, Michigan, knocked out a customer with a single punch.

The incident occurred early last Thursday at around 3 a.m at the McDonald's on Grand River Avenue. A Michigan State University student was hurt in the altercation, but his injuries were not life threatening.

Witnesses described how the student entered the store and proceeded to spit on the counter. This prompted a comment from an employee which drew an angry response from the student, who threw a “caution: wet floor” sign at the worker.

Kevin Lange, who recorded the video, said that another worker was called from the back to escort the student out, and that was when things got out of control.

After the worker dressed in black pushed the student over while escorting him out, the student turned on him. According to Lange, the student appeared “startled and ready to pick a fight.”

The worker dressed in blue then intervened, knocking the customer to the floor with a single blow.

While acknowledging that the student’s behavior had been provocative, Lange questioned the response.

“He definitely instigated it,” Lange said of the student. “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.”

Observers helped tend to his injuries, which included a large gash on his head. He was later taken to hospital.

According to East Lansing police spokesman Steve Gonzalez, no further information on the incident could be released since investigations are still on-going. The student filed a criminal complaint, Gonzalez said.

At this point in time they're still tying up loose ends on it, then they'll refer it to the prosecutor's office for review," he said.