Stephen Power, aged 26, of Gurteen, Inniscarra, Co Cork, pleaded guilty to a charge of assaulting Tony Mullins at the premises on September 10, 2016.
Inspector John Deasy said that when gardaí arrived they found Power being restrained by security staff.
As gardaí were informed the man had assaulted a security man, Power became more aggressive and had to be restrained further.
The inspector said Power hit his head on the ground and was bleeding and needed medical attention. However, when he was being taken back from the ambulance crew into Garda custody, he became aggressive again and had to be pepper-sprayed.
During a routine search in custody, €30 worth of amphetamine powder was found in his pocket. Power admitted having that for his own use.
Eddie Burke, solicitor, said the accused brought €500 to Cork District Court for the injured party.
“He would like to apologise... I have seen the video evidence and no doubt he was extremely intoxicated. He is very ashamed of what happened. It is six years since he was in trouble.”
Judge Aingil Ní Chondúin put the case back until November 28 for a probation report.