A Masterton man is in a critical condition in Wellington Hospital after he was punched in the head and fell on to a concrete driveway on Clyde St on Thursday night.
Police believe a verbal quarrel between two men at neighbouring houses turned violent leaving the victim unconscious.
No arrest has been made and the police investigation is continuing.
The woman who occupied the house, who did not wish to be named, said the man, in his 50s, was her caregiver.
The argument had been brewing for some time before the incident.
"I don't know why he [the victim] was in a mood but he was.
"The other guy could have walked away but he didn't . . .They both could have walked away.
"You always have the choice to walk away."
She said she did not see the altercation because she had gone to get a cellphone to call the police to stop the pair arguing.
"I don't really know what it was about."
She returned to find him unconscious on the driveway.
At first there was just blood coming from his nose, she said, but then the level of bleeding from his mouth became "significant".
"There was lots of blood."
She said she had been told the man was in a medically-induced coma and efforts would be made to try wake him up later this weekend.
Police were called to Clyde St about 7pm on Thursday night and cordoned off the street overnight with a scene guard in place.
Detective Senior Sergeant Barry Bysouth said two people were involved in the incident.
"One party has received a blow to the head and as a result they have hit the concrete," he said.
"Either because of the punch or the fall he is now in critical condition.
"He's got a head injury and we're investigating how he received it."
All the witnesses had been co-operative and police were not looking for anyone else in connection to the incident, he said.
"It is not gang-related and we don't believe it is drug-related.
"I want to reassure the community that we believe this is a one-off incident and there is no reason for the community to have ongoing concerns."
When police arrived at the scene, first aid was being given to the victim by an ambulance team.
Police sealed off the street to allow emergency services to work and detectives were immediately called to the scene, Mr Bysouth said.
"A number of police staff were present to ensure we spoke to all witnesses at the time.
"There were no weapons involved in the assault based on the information we have."
One neighbour said he did not hear anything before the ambulance arrived.
"He was just lying by the steps and a lady was trying to wake him up."
Another Clyde St resident said there were about eight police cars on the street following the assault.