A man has been found not guilty of murdering his ex-girlfriend's new partner after the couple had beaten him up twice.
Prosecutors told a NSW Supreme Court jury in June that Allan Francis Dunbar, 59, murdered Shane Naylor out of jealousy and "mutual animosity" in January, 2022.
The jury heard Dunbar had ended up in hospital after former partner Erin Rogers and Mr Naylor beat him up twice and kicked him out of their house.
Mr Naylor died after being stabbed in the heart during a fight at a Toongabbie home in Sydney's west.
A yellow box cutter and a blade without a handle were found near his body, but Dunbar's DNA was not found on either.
Dunbar acknowledged his difficult relationship with Mr Naylor but he did not stab or even strike him, defence lawyer Josh Brock told the jury.
He said a statement from Ms Rogers pointed the finger at a third man who intervened in the fight and punched Mr Naylor in the head.
Mr Brock argued the man and another witness had deliberately obscured the truth in their accounts of the altercation.
After retiring on Friday, the jury returned its not guilty verdict on Monday.
