Christopher Allan McCulloch, 33, of Whitemore, assaulted Adam Cawthen at the Queens Head Inn at Perth on March 19, 2017.

McCulloch and his wife, Natalie, had gone to the pub with several of her family members.

While McCulloch was playing on a poker machine, his wife pulled a reserved sign - put there by Mr Cawthen's wife, Olivia - from the machine next to his and threw it away.

Mrs McCulloch's brother sat in the chair by the reserved machine as his sister played on a machine beside him.

When Mrs Cawthen came back inside after smoking a cigarette, she spoke to Mrs McCulloch and her brother about the missing sign.

A scuffle eventually broke out, with Mrs McCulloch knocking the glasses from Mrs Cawthen's face.

It was then that Mr Cawthen attempted to push Mrs McCulloch's arm away from his wife. He was grabbed by the throat and pushed by McCulloch who has said he was trying to defend his wife.

McCulloch punched Mr Cawthen twice in the left side of his face, leaving him with a fractured eye socket, a black eye and a small bleed in the white of his left eye.

McCulloch's counsel said that his earlier crime of common assault in 2015 - for which he was given a wholly suspended sentence on the proviso he didn't commit any more offences warranting imprisonment - was partly due to his ice addiction at the time.

The court heard McCulloch had made significant efforts to rehabilitate himself since then and that he lives with his wife, daughter and stepson.

Justice Michael Brett said McCulloch's criminal history was "unremarkable" and he seemed to have had a "wake-up call".

"The crime you committed was a brutal act of violence in a public place," Justice Brett said of McCulloch's assault of Mr Cawthen.

"[But] I accept the reasonable possibility ... you believed that [Mr Cawthen's] actions did constitute a threat to your wife."

Justice Brett told the court McCulloch had cooperated with police.

McCulloch's previous suspended sentence for his 2015 crime was not activated, with Justice Brett saying he'd been persuaded that it would have been unjust to do so.

"My conclusion is that the community will be best served by having you continue your rehabilitation into the future," Justice Brett said.

McCulloch received a nine month jail sentence, wholly suspended on the condition that he not commit another offence punishable by imprisonment in the next 24 months.