Edinburgh Sheriff Court heard today how 19-year-old James Addison struck a steward as a “large melee” broke out in the away stand.
The atmosphere had intensified during the crunch match in May after Wilson ran onto the pitch and approached the Celtic boss.
Addison, a plumber from Cumbernauld, was fined £1000 after pleading guilty to the offence.
He claimed he was trying to help a friend who was being held by steward Graeme McKechnie as bedlam broke out among the Celtic support, who clashed with police.
Sheriff Kenneth MacIver did not hand down a football banning order, but added that the Glasgow club may take their own action.