Przemyslaw Trebacz, aged 35, of Bramble Rise, Killynebber, Cavan, had pleaded not guilty to the murder of Costel Catalin Cretu, aged 38, at Connolly Court, Connolly St, Cavan, between Oct 13 and 14, 2012.
He had pleaded guilty to criminal damage to a door belonging to Brendan Cosgrove at Connolly Court on Oct 13, 2012.
The Central Criminal Court heard Mr Cretu was stabbed once in the chest and once in the back and died at the scene.
The jury of nine men and three women returned the majority verdict of 10-2 after almost 10 hours of deliberations.
Mr Justice Barry White thanked the jury before excusing them from further service for life.
He adjourned sentencing at the request of the defence until Jan 20 next when a victim impact statement will be read to the court.
It was the prosecution’s case that Trebacz went to the apartment to carry out a robbery and brought a weapon with him.
Trebacz denied bringing a knife with him and said he was going to the brothel to visit prostitutes with another man.
He told gardaí he paid Mr Cretu €80 for a half hour but the door shut in his face.
Trebacz told gardaí he kicked the apartment door in and struggled with Mr Cretu before he stabbed him but said he was acting in self-defence.
He denied stealing money from one of the prostitutes and said he had a letter from his solicitor saying he was getting an apartment with €74,000 from his mother’s will.
Paul Greene SC, defending, raised the defences of provocation and self-defence during the trial, which started on Nov 28.