Wigan forward Will Grigg scored just over ten minutes from time in order to claim a shock 1-0 win for the hosts against Manchester City.
The resulting celebrations involved home supporters invading the pitch, and Sergio Aguero becoming caught up in an altercation with a fan as the players were escorted off.
Supporters then turned violent, ripping out advertisement boards and hurling them towards to police.
The FA fined Wigan £12,500, who accepted the charge, for: ''Failing to ensure that no spectators or unauthorised persons encroached onto the pitch.''