Friends turned foes when a Whanganui man showed up at an address, knocked on the door and attacked the man who answered.
Thomas Kane Gartner appeared in Whanganui District Court on Tuesday having pleaded guilty to common assault.
He was sentenced to 120 hours' community work by Judge Garry Barkle.
Police prosecutor Stephen Butler told the court the victim was an old work colleague whom Gartner claimed owed him $200.
The victim disputed this and a brawl erupted.