Redford Kaea was "smashing" his father-in-law with his fists in a fatal fight, according to a key witness.
Kaea, 26, is on trial in the High Court at Rotorua after pleading not guilty to the manslaughter of his father-in-law, Michael John Anderson, in Rotorua on February 1 last year.
Anderson suffered severe head injuries and spent 13 days in the intensive care unit at Waikato Hospital before dying from blunt force trauma to his head.
Kaea admits physically fighting with Anderson on the day but says he was acting in self-defence as his father-in-law was trying to stop him from leaving the property.
The trial is before Justice Andru Isac and a jury.
Crown witness Morgan Hamiora-Smith gave evidence today and testified he saw the two men, who were his neighbours living in units on Malfroy Rd, get into a "scrap".
They were fighting each other but eventually, Kaea got the better of Anderson, Hamiora-Smith said.
"He (Anderson) tried to attack Radford but he was not tough enough ... He got smashed ... He was slamming him around with his fists."
Hamiora-Morgan said he went to call 111 and came back to see Kaea driving away.
"He (Anderson) was on the ground unconscious. I think he was breathing."
When asked by Crown prosecutor Anna McConachy if he noticed any blood on Kaea, Hamiora-Morgan said he didn't see any.
Under cross-examination from Kaea's lawyer, Bill Nabney, Hamiora-Morgan said Anderson was trying to stop Kaea from leaving.
Nabney asked if Kaea was lifting Anderson up to get him away from the cars, but Hamiora-Morgan said he wasn't sure.
The trial started on Monday with McConachy outlining the Crown's case to the jury. She said Kaea and others lived in a unit in a group of flats on Malfroy Rd and Anderson and others lived in a neighbouring unit.
The two groups didn't get along and Kaea and those at his home had intended to leave and move to Auckland. Anderson tried to stop them from leaving.
A fight broke out between Kaea and a woman, who has interim name suppression. Anderson stepped in and began fighting with Kaea.
The trial is expected to last until at least the end of this week.