Rimi Abraham, 24, pleaded guilty in Dandenong Magistrates Court to affray, recklessly causing serious injury and shop theft.

He also pleaded guilty to a string of other offences, including an assault in South Yarra, obtaining property by deception and speeding 100kmh over the 80kmh limit on the Monash Freeway.

The court heard that Upper Beaconsfield truck driver Shane Cahill, 48, was severely beaten by Abraham and a co-offender about 10.30pm on November 9 last year at a BP service station in Clyde Road.

Prosecutor Sean van Geyzel said Abraham had stuffed two baseball caps under his jumper and was racially abusing the attendant when Mr Cahill entered and told him to "calm down".

Abraham abused Mr Cahill, grabbed him and started wrestling.

The other man accompanying Abraham returned and the pair punched and kicked Mr Cahill, even when he lay unconscious.

"They stomped on his head at least 10 times," Senior Constable van Geyzel said.

Rob Melasecca, who represented Abraham, argued his client should not be jailed as the community would be best protected by him undergoing impulse and anger management programs under an intensive correction order.

Mr Melasecca said Abraham's inability to deal with frustration stemmed from a horrific childhood in which the whole family had suffered physical abuse at the hands of his father.

"This is a man who is trying hard. His being sent to jail will not be in the best interests of the community."

Magistrate Pauline Spencer sentenced Abraham to a total of 18 months' jail for all the offences. He must serve a minimum of eight months.

Ms Spencer, who took Abraham's age, remorse and violent childhood into account, said she did not believe he was beyond rehabilitation. But she described the assaults as being of a "savage and extreme nature" in which the victims were lucky to not have died or suffered more serious injuries.

Ms Spencer also ordered Abraham to take part in a violence-intervention program in jail and if paroled.

When being escorted out, Abraham thanked Ms Spencer and vowed: "I won't be back".