Detective Senior Constable Alex Fiore commended Mr Irwin's bravery.
"An innocent man was just in the backyard with his family and has come to the aid of a neighbour, and unfortunately been attacked himself.
"The victim is extremely brave.
"I know the occupants of this address are very grateful for his involvement," he said.
Detective Senior Constable Fiore said detectives were trying to establish if the victims of the invasion knew the offenders.
"Police are investigating whether the home invasion was targeted or an isolated incident," he said.
"We think there may be a relationship but we're not sure."
Witnesses told 9News the offenders were demanding money and fled when it became clear they were not getting any.