A 22-year-old man has been convicted of the manslaughter of student Brian Murphy in August 2000.
Dermot Laide, of Rossvale, Castleblaney in Co Monaghan, was also found guilty of violent disorder.
Co-defendant Andrew Frame, 22, of Nutley Lane, Donnybrook in Dublin, was found not guilty of violent disorder. He had already been acquitted of manslaughter on the directions of the trial judge.
The jury of eight men and four women returned to Dublin Circuit Criminal Court with its verdicts just after 6.30pm.
Judge Michael White heard Laide had been found guilty of manslaughter by a 10-2 majority verdict and guilty of violent disorder unanimously.
During the trial, witnesses said Laide was in a group attacking 18-year-old Mr Murphy outside a nightclub at the Burlington Hotel in Dublin.
He threw a punch, or punches, and kicked the student in the shins. The prosecution claimed a cut on Laide's hand was from a punch to Mr Murphy's mouth.
The jury will resume their deliberations in the case of two remaining accused, Desmond Ryan and Sean Mackey, in the morning.
