The security guard was trying to stop a Stockport County fan from invading the pitch during a football match with Yeovil Town.
Jamie Williams, a recruitment consultant was boozing and high on drugs when he punched the security guard in the face.
Williams, 30, of Ratcliffe Street, Stockport pleaded guilty for the assault and possession of cocaine.
He was due to appear before the court on April 30 but a warrant was issued after he failed to turn up.
The security guard said he suffered pain at the time of the assault but had no lasting injuries.
The magistrates imposed a 12 month conditional discharge for the assault and fined him £107 for possession of the cocaine along with £85 costs and a £30 victim surcharge.