A young father of three was "let off the leash" by his partner, and got drunk and high, before a dispute over him kissing another woman led to a fatal one-punch attack, Victoria's Supreme Court has heard.
Richard Andrew Vincec, from the Geelong suburb of Herne Hill, has pleaded guilty to the manslaughter of 22-year-old Jaiden Walker after leaving Cherry Bar in AC/DC Lane in Melbourne's CBD in May.
In the hours leading up to the fatal punch, the 26-year-old labourer drank alcohol with friends at a Carlton football match, a pre-sentencing hearing was told.
Defence lawyer Robert Richter QC sad Vincec had been "let off the leash" by his partner and took speed and cocaine.
Security camera vision played in court showed Vincec in the street outside the bar kissing another woman, with whom Mr Walker had previously been in a sexual relationship with.
Mr Richter said Mr Walker clearly got upset, the situation became hostile and Vincec tried unsuccessfully to shake his hand.
"This is very upsetting to Richard Vincec because all he wants to do is shake hands," Mr Richter told the court.
The men did eventually shake hands in an "aggressive manner" before Vincec punched Mr Walker in the left cheek, causing him to fall back and hit his head on the ground.
He died in hospital several days later after suffering a fractured skull and bleeding on the brain.
Mr Richter denied it was an example of what is known as a "coward's punch", saying it was "not a heavy blow" and the victim's fall was made worse by the fact he was also drunk.
"If Jaiden had not had that level of alcohol content, he would not have fallen or he would have protected his fall," Mr Richter said.
He urged Judge Peter Riordan to show mercy on his client when he is sentenced, saying it was not the most serious example of manslaughter and the penalty should be in the range of three to four years' jail.
"The only reason he is going to jail is because the notion of general deterrence requires it," Mr Richter said.
"The degree of remorse is extraordinary here."
Father 'cannot accept' he lost son to violence
Vincec appeared nervous and agitated throughout the hearing and took deep breaths to calm himself.
The court heard Vincec had previous convictions for violent offending and had written an apology letter to the victim's family.
Mr Walker's father Jon Walker fought back tears as he told how the senseless act of violence had taken the life of his honest and respectful son.
"Jaiden wanted to save some money to travel and start a small business," Mr Walker said.
"I was looking to a future with my son but all of this came to an end.
"I lost my son to an act of violence and I will never accept that."
Prosecutor Peter Rose rejected the notion that the offending was at the lower end of the scale and asked that Vincec's bail be revoked.
He was taken into custody to be sentenced at a later date.