Mohammad Mohammadi was lying on the ground and bleeding from his chest - alone, frightened and defenceless - when two men kicked and stabbed him after a violent brawl.
He died in hospital from his injuries one day after his 18th birthday.
Victorian Supreme Court justice John Champion described the violence as "gratuitous and spiteful", as he sentenced Alith Wal, 20, and Nyal Mainyal, 22, to terms of imprisonment on Wednesday.
Both men pleaded guilty in February to affray and intentionally causing injury.
While they did not inflict fatal injuries upon Mr Mohammadi, who died because another man stabbed him in the chest, they stabbed him in his leg and arm while he was lying on the ground, bleeding.
"Your actions must have added significantly to his trauma and misery in circumstances where he had been abandoned by his so-called friends and was alone and at your mercy," Justice Champion said.
"You showed no mercy and you then attacked him with your feet and your knives. The level of violence and the gratuitous nature of it was abhorrent and offends basic human decency."
Mr Mohammadi was part of a group of six who went to Corio shopping centre, north of Geelong, to fight another group - including Wal and Mainyal - on August 23, 2020.
He got between the two groups to stop the brawl when he was stabbed in the chest.
"I've been stabbed with a weapon," Mr Mohammadi cried out, before walking away and falling to the ground.
Holding knives, Wal and Mainyal surrounded Mr Mohammadi, who was alone, defenceless and lying on the ground with blood on his stomach. They stabbed him in his thigh and armpit.
Mr Mohammadi was taken to hospital and underwent emergency surgery but was later declared brain dead and died on August 29.
His mother was planning his 18th birthday party when she found out he had been stabbed.
"She says that even in the years that have passed since the loss of her son, she feels that her grief and pain have only increased further," Justice Champion said, reading her statement.
"What happened to her son deprived her of the opportunity of a life and she will live the rest of her life with a hole in her heart."
Wal was handed a six-month prison sentence and Mainyal given nine-months. However, they will be released shortly on to community work orders, as they have been in prison for more than two years.
A third person, who was aged 16 at the time of the offending, was last month acquitted by a jury of murder for his role in the attack.
