Tamati James Lee Ruru, 21, had admitted the charge of causing grievous bodily harm with intent to injure in the Westport District Court, but the case had been transferred to Christchurch for sentencing by the same judge.
Ruru wrote a letter of "unreserved apology" to the victim for the hurt and suffering he had caused. The judge read all of it out in court.
Defence counsel Douglas Taffs urged that community detention be imposed to allow Ruru to get further trade training.
He had effectively been disqualified from driving for a year because of his bail conditions, so he urged that no further disqualification be imposed because his licence would be important for work as a panelbeater.
The incident took place on January 9, 2021. Ruru had been in a relationship with a woman but it ended in 2020 and she took out a protection order against him, and began a relationship with the victim of Ruru's offending.
Ruru found on January 9 that his car's back windscreen had been smashed. He tried to report the damage at the Westport Police Station but no staff were available so he decided to take matters into his own hands.
Suspecting the woman's new partner, he drove to the man's address, going past several times in an attempt to get him outside. He then yelled and screamed from his car until the man came out.
When the man came out and stood on the road verge, Ruru deliberately drove into him, causing him to be thrown up onto the windscreen and rolling off the side.
The windscreen was shattered. Ruru drove off without stopping.
The victim was flown to Christchurch Hospital with abdomen, chest, and back injuries. He needed three hours of surgery for a broken back.
Judge Gerard Lynch said the victim's report said he was recovering well, and was "generous and understanding".
The victim offered to meet Ruru and his family so that "some sort of peace can be found, to move forward".
A pre-sentence cultural report said life had been difficult for Ruru, with a traumatic and chaotic childhood.
Judge Lynch said no-one in court saw Ruru as "a write-off, without hope", but he could not reduce the sentence as far as community detention. He imposed nine months' home detention in Christchurch, with a direction to attend training programmes and counselling as required by his probation officer.
He gave Ruru a first strike warning, and imposed 18 months' driving disqualification, backdated for one year to the start of his driving ban bail condition.