Officers found him in a serious condition with a single stab wound to his head.
He was rushed to Auckland Hospital where he had surgery.
The elderly man was reported to be in a stable condition this morning.
Police were seeking the weapon thought to have been used in the attack.
They were still at the house this afternoon which remains cordoned off. Police could be seen in the front room of the house and are searching the gardens of neighbouring properties.
Neighbour Tony Compain said he was shocked to hear his close neighbour had been taken to hospital.
"He's a nice man and he wouldn't harm anyone,'' Mr Compain said.
"We didn't hear or see a thing - our house is set back from his house and we have a big garage in front of us. It wasn't until he was taken away that the officer came and asked us.
"We were told the man was in a critical condition last night and that he had improved this morning.
"We are Jehovah's Witnesses, so we preach about how bad this world is every day _ this is just proof it's a lousy world we live in,'' he said.
Mr Compain said he talked with his neighbour every day because he didn't have many immediate family members.
"We keep an eye on him.''
Another neighbour, who did not want to give her name, said her house had been broken into twice in the last year and there had been other break-ins in the area but no one had been hurt before.
She said she had known the elderly man for more than 20 years.
"You would only need to back off and he wouldn't hurt you.''
She said the elderly man told her about two weeks ago that he thought he heard someone on his deck at night.
"He's a lovely neighbour who minds his own business and lives on his own.''
Another neighbour, who also did not want to be named said the elderly man enjoys gardening.
"I don't know why anyone would do that to him. He never did anything wrong. It's frightening ... This whole business has upset me, I live on my own.''
