A man who sprayed his ex-partner with petrol and threatened to burn her alive has been sentenced to two years and three months in prison.

Jason Robert Hayward, 46, appeared in the Hamilton District Court on Monday on charges of threatening to kill, burglary, and male assaults female.

The court heard how Hayward had modified a fire extinguisher and filled it with petrol before travelling from Mangakino home to the woman's Hamilton home on December 10, 2015, reports Fairfax .

Hayward had been in a relationship with the woman for several years and was texting her saying he wanted to visit to obtain 'closure”. She initially agreed, but then texted him back asking him not to come.

The woman was at the home with three others when Hayward appeared on her doorstep at 6.30pm with the fire extinguisher in hand. While in the doorway he began spraying his victim.

Some of the petrol also sprayed the woman's companions and it got into their eyes and blurred their vision, as well as burning their skin. The four fled inside the house, but Hayward followed them in and continued to douse his ex-partner with the fuel.

At one point Hayward grabbed his ex-partner by her hair and dragged her across a room. He then ordered his victims to each hand over their cellphones before he took out a lighter from his pocket, moved towards his ex-partner, then lit it.

It was at this stage one of the woman's companions jumped through a window and ran to a neighbour's house to raise the alarm. Hayward doused the lighter and put down the extinguisher, and one of two remaining companions seized the opportunity to grab the fire extinguisher.

Hayward was coaxed outside and had fled the scene by the time police arrived shortly after.

The following day, Hayward went to the Hamilton Police Station and handed himself in.

For 10 months after the incident Hayward denied he'd committed the three charges but eventually pled guilty to the offending shortly before the reserve date of his trial in late October.

Judge Snell says Hayward committed 'effectively, a home invasion” that could have ended 'in a fraction of a second either accidentally or deliberately engulfing [his victims] in flames,” reports Fairfax.

Prior to sentencing, Hayward's counsel Roger Laybourn told the court all his client had intended to do was frighten his ex-partner to deter her from alleged drug use, adding that his client had been suffering from anxiety and depression which had manifested in his ill-conceived plan.

And while Hayward has 35 previous convictions, none involved violence so this was 'very out of character for him.”

A pre-sentence report found Hayward had some insight into his offending and empathy towards his victims. He was also determined to change for the better.

- Stuff.co.nz