But a jury cleared them of the charge and instead convicted them of affray and aggravated burglary.
The victim’s mother, Snezana Dimovska, who flew from Macedonia to hear the case, broke down in tears outside court.
“They stabbed him for nothing – for nothing,” she said.
“When’s my son going to see the sun?
“When’s my house going to be happy?
“I just have one son.”
Relative Mary Dimcevska said the family had been denied justice.
“They go home to bed and our boy will never come out of the hole again,” she said.
Mrs Dimcevska said Deni and his friend had organised the event at the restaurant that night for a singing performance.
“Deni was a very lovely boy. He never got into any trouble. All he said was, ‘can you please stop pushing the tables in the restaurant’. From that, it all happened.”
Justice Michael Croucher said on Tuesday both accused were of otherwise good character and had a strong chance of rehabilitation.
The pair will be released after serving almost two years in custody awaiting sentence.
The men’s lawyers had argued the brothers had served enough jail time and should not be punished further.
Another man, Milos Novakovic, will face a plea hearing in July after he was convicted of Mr Dimovski’s murder.
Last year, brothers Stefan Obradovic and Daniel Obradovic, both in their 20s, and friend Stephen Motta, escaped conviction and were ordered to do unpaid community work over the affray.