Hirini Sidney Mate, 41, was jailed for four years 10 months when he was sentenced in the Dunedin District Court in July.
But in the High Court last month, Justice Anne Hinton said Judge Michael Turner should have given the defendant greater concessions for his guilty plea and turbulent upbringing.
On September 26 last year, Mate was issued with a police safety order banning him from contact with his partner.
Within hours, he turned up at her home, damaged her property and punched her face.
Mate contacted her again on November 16, hoping to meet up, but when she refused he became abusive and threatening, the court heard at sentencing.
As the woman was getting out of the shower, Mate turned up at her door.
The defendant grabbed a boning knife from the kitchen and held it towards his partner, repeatedly claiming he would kill her.
He then hit the woman in the face, knocking her on to the couch, before punching her repeatedly and kicking her five times in the head.
The victim sustained a fractured eye socket, multiple fractures to her nose, grazes, significant bruising and needed nine stitches to her face as well as surgery to repair her nose.
A report charted Mate’s upbringing, including his exposure to violence and drugs before coming under the stabilising influence of his grandparents.
Judge Turner said the couple provided him a loving home, instilled strong values and the defendant gained employment when he left school in sixth form.
But Justice Hinton said the negative influences in Mate’s life were largely overlooked.
"In my view, Mr Mate’s early separation from his parents, his exposure at a very young age to family violence, alcohol and drugs when he stayed with his parents in the school holidays, the loss of his koro/grandfather when he was still a teenager, and his grandmother a few years later, his gang affiliation and later cultural isolation are all factors that call for recognition as causative contributors of his offending," she said.
Mate’s life spiralled and at the time of his crimes he was homeless and trying to support himself and his partner, the judge said.
"He was at rock bottom," Justice Hinton said.
"If these background factors had not all been part of Mr Mate’s life, stemming from an early age, it is doubtful he would have committed the present offending."
She quashed the sentence and replaced it with a sentence of three years 10 months.
