A group of men acted "like a pack of animals" when they attacked a hospital worker following a row in a pub on Halloween, the Old Bailey has heard.
Richard Price, 23, who worked at Great Ormond Street Hospital, died three days after the "brutal" attack in Bromley town centre on 31 October.
He was stamped and kicked after refusing to buy Murat Karabeyaz a drink in the Swan and Mitre pub.
Mr Karabeyaz, Param-Jit Theara, Jagtar Johal and Michael Liddell deny murder.
The court heard Mr Karabeyaz, 25, of Catford, south London, had bought the victim a drink, but Mr Price refused to return the gesture which led to a row in the pub.
Mr Karabeyaz, Mr Theara, 25, of Eltham, south London, Michael Liddell, 20, of Ealing, west London, and Jagtar Johal, 37, of Bromley, all admit being in the alley where the fatal attack took place but deny attacking Mr Price or using any unlawful violence.
Mr Price, who died of a head injury, was "brutally assaulted" in an alleyway beside the Empire cinema, Jonathan Rees QC, prosecuting, said.
He said: "He was knocked to the ground and kicked and stamped upon.
"The injuries that he suffered revealed that his attackers were particularly targeting Mr Price's head.
"Some of those who witnessed the sickening attack described the behaviour of the group being like a pack of animals."
The trial continues.