A witness at a manslaughter trial told a jury he saw the accused man sitting on the victim's chest and beating his head on the ground while encouraging another man to kick him in the head.
Mr John Copperthwaite told the Dublin Circuit Criminal Court jury that the victim was lying motionless underneath Mr William McDonnell with several bruises on his face and ears and one of his eyes was completely shut.
The third man who was standing beside the other two men kicked Thomas Maloney in the head or the face several times in response to Mr McDonnell's shouts.
Mr Copperthwaite, part of a father-son musical act who gave his stage name, John Stone, to gardaí immediately after the event, agreed in cross-examination by Mr Anthony Sammon SC , defending, that he wanted to see Mr McDonnell "go down".
He also agreed that he saw himself as a "popular vindicator" who was going to "sort everything out" because he "saw everything".
Mr Copperthwaite was giving evidence in the trial of Mr McDonnell (39), Mary Aikenhead House, James's Street, who has pleaded not guilty to three charges arising out of an incident at the Statoil service station at Usher's Quay.
He denies the unlawful killing of Thomas Maloney (27), Cosgrave Park, Limerick on May 3rd, 2002, and two further charges of assault causing harm to Mr Maloney and reckless conduct which created substantial risk of harm to him on April 21st, 2002.
Mr Copperthwaite agreed with Mr Sammon that he did not see how the fight started, but saw how serious the fight was and had shouted at the two men to leave Mr Maloney alone.
He said Mr McDonnell responded to his shouts and climbed off the victim. He said he then punched the other man who had been kicking the victim with his right leg when he came towards him. This man then backed off and left the area.
Mr Copperthwaite said Mr McDonnell had walked around the forecourt of the filling station shouting before leaving on a bike which had been parked near one of the pumps. There was a cut on his nose which was bleeding quite heavily.
Mr Copperthwaite said he went over to the victim who was still motionless.
There was a lot of blood and his face was heavily bruised. He thought he had a cut on the back of his head as well.
He then laid the victim on his side, afraid that he might vomit and choke.
He had started "coming around" and appeared better by the time gardaí and an ambulance arrived and removed him to the hospital.
Mr Fergal Foley, prosecuting, had told the jury in his opening statement that after being conscious briefly at the filling station, when he asked for a cigarette, Mr Maloney lost consciousness and never regained it.
Mr Maloney, who would have been 28 last week, died as a result of injuries he had sustained to his brain.
Earlier witnesses, including two Chinese students who were working at the 24-hour filling station, told the jury they had observed a fight involving three men in the forecourt.
The salesgirl said she remembered Mr Maloney asking for a bottle of white wine, a product which the shop did not serve. She had then become busy with other customers when shortly afterwards she heard two men fighting. One of them was Mr Maloney.
She dialled 999 after a customer had urged her to. The other sales assistant on duty that night said he saw the fight on the CCTV monitor.
He agreed with Mr Sammon that fighting was not a new thing at the station at that hour of the night but said that normally they were "not fights like that".
The hearing continues before Judge Yvonne Murphy.