The lawyer said his client had a drinking problem.
A letter of remorse from Wharehinga was handed to the judge to read.
However, Judge Bergseng said this was the third breach of the protection order by Wharehinga.
The summary of facts that was released to the Times-Age by the judge, states on January 4 the couple of four years were at home in Masterton when Wharehinga heard a conversation his partner was having on the telephone.
He accused her of talking with another man and started yelling at her.
She went into the laundry and sat on the freezer to have a cigarette when she saw Wharehinga walk through the kitchen, grab the car keys off a hook. She then saw he had a large carving knife in his hand, the summary states.
He drew the knife back and stabbed it into the wall a door width away from the victim's head. She tried to leave the property in her car, but Wharehinga tried to stop her by closing the farm gate.
She escaped by driving through the gate.
After convicting Wharehinga, Judge Bergseng said a pre-sentence report was needed to assist the court at sentencing.
"Sentencing needs to be structured. He was very drunk at the time."
Wharehinga was remanded in custody for a pre-sentence, drug and alcohol report.
He is due back in court March 13 for sentencing.