Maitae Hereva was convicted over the killing of Morgan Ido on Thursday by Justice George Manuhu.
The Waigani National Court ran a trial against the Gulf man after he pleaded not guilty to the charge of murder.
He was however convicted for manslaughter after the court saw that he had no intention to kill.
He will return to court later this month where submission will be made on what his appropriate penalty should be, with the assistance of the pre-sentence report.
On May 22, 2015, Hereva and Ido were involved in a fight. Three punches were given by Hareva after he found that K300 went missing from his pocket.
Ido was punched on his forehead and the back of his head, causing him to fall forward. Medical reports showed that he had internal bleeding as a result of the fight, causing his death.