The victim was later taken to hospital for treatment for his injuries.
The alleged attacker had been in a previous relationship with the female occupant of the house.
Mr Baddock said the man was well-known to Westport police.
He had been charged with aggravated burglary, injuring with intent to cause grievous bodily harm, trespass, and threatening to kill.
He was currently in police custody and police would oppose bail, Mr Baddock said.
Meanwhile, police are warning Westport bars to be wary of selling booze to anyone who's drunk.
The warning follows an alcohol-fuelled brawl on Boxing Day night outside the Criterion Hotel on Palmerston Street.
Mr Baddock said the fight erupted after drinkers in the hotel hit the street.
"A number of patrons spilled out from that hotel and began fighting. Police are investigating and will be looking to identify offenders from video footage.
"Anyone who can be identified fighting can expect to be charged."
Mr Baddock warned bars not to sell alcohol to drunk customers.
"We have noticed a considerable surge in offending for the time of year, in relation to liquor. That includes disorder and domestic violence - all alcohol-related.
"Police are urging liquor licence holders, and suppliers of alcohol, to be conscious and wary of who they are selling to, that they are not intoxicated."
Mr Baddock said the influx of people from out of town sometimes provoked locals, who didn't want to share their liquor, to start fights.
