A man who fatally stabbed his half-sister's partner as the victim sat helpless in his car with his seatbelt on has been jailed for at least six years and three months.
His half-sister had testified to seeing her partner of 26 years die in front of her as she sat beside him.
Justin Fuller, 33, used two machetes to stab Guy "Wink" McCulloch during the frenzied attack in Belmont South in December 2018 after a long-running feud.
The Crown had not accepted his guilty plea to manslaughter, but a jury in September acquitted him of the more serious charge of murder.
In the Newcastle Supreme Court on Monday, Justice Richard Cavanagh jailed him for nine years, with a non-parole period of six years and three months.
The stabbing took place after Fuller was a passenger in a Holden Commodore driven by his then girlfriend, Narelle Abercrombie, when they passed his half-sister Kristy Duley and Mr McCulloch parked and talking to friends.
The jury was told Ms Duley called out "Tick Tock" to Ms Abercrombie and she gave her the finger.
Fuller later approached Mr McCulloch's Nissan Navara on foot and argued with his sister and her defacto before Mr McCulloch twice reversed his car into Ms Abercrombie's Commodore, stopped directly behind him.
The trial was told Fuller went to his home nearby and grabbed a backpack with the two large knives before walking back to the Navara where Mr McCulloch and Ms Duley were still seated inside.
Fuller reached through the driver's side window and stabbed him with the machetes four times.
Mr McCulloch, 50, went into cardiac arrest and one deep penetrating stab wound to the liver caused him to bleed to death.
The defence contended Fuller had been provoked and had lashed out in self-defence and referred to a longstanding toxic relationship between Fuller and Ms Duley.
Fuller told the jury he "lost it" after the confrontation with his half-sister and Mr McCulloch, and did not remember he was carrying two machetes.
He claimed Mr McCulloch had reversed at him, trying to run him over and he had jumped out of the way before clinging to the side of the car.
Fuller said he only intended to punch Mr McCulloch through the open car window, not stab him.