Auckland man Ben Bosch Herkt - who was found guilty of murder today - was angry after being punched in the face during a drunken fight.
The High Court in Auckland heard how after being locked outside the unit where he was drinking in November last year, he went to the neighbour to ask for a cricket bat.
When he was told the bat was broken, he asked for a knife, before returning next door to break in and repeatedly stab Matthew Greenslade.
Herkt's lawyer had argued his client did not have the required murderous intent. Peter Kaye said Herkt was a paranoid schizophrenic and his medication had been effected by the alcohol.
But the jury took took less than two hours to find him guilty of murder today.
In his summing up today, Justice Moore told the jurors their verdict would depend on what they believed was going through Herkt's mind at the time of the attack.
He said there was no dispute that Herkt fatally stabbed Mr Greenslade a year ago.
Justice Moore told the jurors that no one goes around with neon signs on their foreheads, announcing what they were thinking.
He said the jurors would have to draw inferences from the evidence about what was going on inside Herkt's head when he inflicted the fatal wound to Mr Greenslade's heart.
That evidence included an initial fight, which started over missing cans of bourbon and cola pre-mix drinks.
Crown prosecutor Gareth Kayes said Herkt wanted revenge after being punched in the face.
Herkt initially lied to police about gang members carrying out the attack before coming clean and admitting that he had done it.
He later told police that he didn't think and should have just shaken Mr Greenslade's hand.
A fight over drinks
The court heard the fight started after the pair had been drinking at Mr Greenslade's Papakura unit.
They had visited the local liquor shop together to get a box of premixed bourbon and cola on credit, with Mr Herkt putting up a gold chain and Mr Greenslade leaving his driver's license.
But an argument broke out when it appeared some of the cans went missing.
The court heard how Mr Greenslade landed a couple of punches to Herkt's face before locking Herkt and his girlfriend out of the unit.
But Herkt didn't end it there. He went next door, borrowed a knife and then kicked the back door in before repeatedly stabbing Mr Greenslade. His girlfriend disposed of the knife.
Mr Greenslade's friends put him in a van and drove him to the local accident and emergency clinic.
On the way there Mr Greenslade was able to talk about his wound, but collapsed at the clinic and despite the best efforts of emergency staff, Mr Greenslade died.
Herkt dropped his head as today's verdict was read out.
Justice Moore thanked the jury for their diligence and also passed on the gratitude from Mr Greenslade's family who he said had sat through the trial with dignity.
Herkt will be sentenced next month.