Bruce Steensen didn't see the blow that killed him.
But his mother, Gloria, hopes his attacker will see her face if he ever thinks to throw another punch.
Jesse James Patrick was behaving aggressively after drinking with friends at Mooloolaba Esplanade on Queensland's Sunshine Coast in February 2014 when Mr Steensen told him to "pull your head in dickhead".
The 21-year-old New Zealander challenged the 53-year-old to a fight and a scuffle broke out between them.
Patrick had a history of violence and was on parole for assaulting his older neighbour only months earlier.
Neither man landed a damaging blow, but as Mr Steensen walked away Patrick became incensed and wanted to finish the fight.
He ran after Mr Steensen and punched him in the back of the head, causing him to fall and hit his head on concrete - fatally fracturing his skull.
Patrick, now 23, pleaded guilty to manslaughter in the Brisbane Supreme Court on Monday and was sentenced to eight years' jail.
He cried as Mr Steensen's mother read out her victim impact statement in court, telling him all she wanted was his rehabilitation.
"You can't go through life treating people like a punching bag," Mrs Steensen said.
"Please don't let it happen again.
"There is no shame in just walking away."
Chief Justice Catherine Holmes said Patrick's offending was at the upper end of the scale and did not set a parole eligibility date because of his history of indifference.
"Mrs Steensen has very movingly and profoundly spoken for your need for rehabilitation, if you are not moved by what she said you are beyond hope," Ms Holmes said.
Defence lawyer Simon Lewis said it was likely Patrick, who has lived in Australia since he was 11 and is a permanent resident, would be deported to New Zealand at the end of his sentence.
Outside court, Mrs Steensen said she did not hate Patrick because it would only hurt her.
"He turned around and said he was sorry so I think we're off to a good start."
