When a bystander saw a man throw his partner against a fence and threaten to kill her she stepped in - and got punched in the face.
But it did not stop her leading police to the violent offender.
Hayden Wereta (28), a father of four, appeared in the Dunedin District Court yesterday after he admitted assaulting a female, threatening to kill and assault.
The court heard, with the support of his mother, he was a committed parent.
''We want to make sure you're not only a good dad but a good person,'' Judge Michael Crosbie said.
Wereta was socialising in Mosgiel with his then partner on August 24.
''You were drunk as,'' the judge said.
The woman told Wereta she wanted to end their relationship, which resulted in his violent meltdown.
At 1.30am, a St John staff member at the station on Harststonge Ave heard a scream and saw the defendant chasing the victim.
''You're going to get it. I'm going to kill you,'' Wereta said.
The witness saw him grab the woman by the scruff of the neck and called police when he lost sight of the pair.
As they walked to Gordon Rd a Good Samaritan saw Wereta force the victim against a fence.
The passerby was hit in the mouth as soon as she tried to intervene.
But as Wereta staggered off, she followed him.
Ambulance staff tended to the defendant's partner while the second victim was able to direct police to her attacker.
Officers found Wereta in the back of a parked car.
He was too drunk to give a coherent explanation for his actions, the court heard.
Defence counsel Deborah Henderson said her client accepted he had a problem with alcohol which needed to be tackled.
She produced a letter from the principal at the school Wereta's children attended, which commended the job he was doing.
Ms Henderson argued it was in the children's best interests their father remain in the community to care for them.
While conscious of Wereta's previous violence convictions, Judge Crosbie agreed.
Judge Crosbie sentenced Wereta to 10 weeks' community detention and 12 months' supervision.
