Crown prosecutor Claire Middleton told the court Rei and Taniwha got into a heated argument and he punched her several times.
He then followed Taniwha into the kitchen and pushed her before she pushed him back.
Rei then punched the woman more than once in the mouth area, hard enough to knock out some of her bottom teeth, Middleton said.
Taniwha then threw an empty litre spirit bottle at Rei.
He then left the house and headed back to his unit, which was behind the address but Taniwha followed with a knife she grabbed from the kitchen, Middleton said.
Police were called and Rei was arrested.
Defence lawyer Raukawa Simon said Rei hit the woman in self-defence.
Simon said Taniwha had become angry, sworn at Rei, hit him with a spirit bottle, punched him and assaulted Boyd to get him out of the way so she could continue the attack on Rei.
Rei had hit the woman in an attempt to escape and head home, she said.
"The punch had the desired effect, it stopped her in her tracks."
However, Taniwha had followed Rei with a 300mm butcher's knife and she could be seen on CCTV bashing through a 1.8m fence to continue the assault, Simon said.
Rei was under no obligation to give evidence in his defence, but he would.
"He was never given an opportunity, in June last year, to explain what happened to police."
The trial is set down for two days.