Keith Wright, 50, was subjected to a sustained attacked as he was waiting for a bus in York in January.
A jury at Leeds Crown Court heard how Liam Matthew Wyard, 20, left Mr Wright fighting for his life with serious brain injuries after punching him to the ground and then kicking him in the head as he lay unconscious on Acomb Road in the city.
Wyard, who had been living in a hostel in York, was jailed for life today and told by Judge Guy Kearl QC he must serve 12 years before he is considered for release, North Yorkshire Police confirmed. He was found guilty of murder on Friday.
Aaron Wootton, 17, formerly of Burnsall Drive, York, was found guilty of manslaughter for his part in the attack and was jailed for three years, police said.
Mr Wright never regained consciousness and died 10 days later in Leeds General Infirmary due to the severity of his injuries.
Both defendants, who had been drinking together earlier, denied murdering Mr Wright.
After today’s sentencing, Detective Sergeant Steve Wilson, of York CID, said: “Mr Wright died as a result of a brutal and unprovoked attack.
“He was minding his own business while waiting at a bus stop when Wyard and Wootton, who did not know him, attacked him for no apparent reason.
“They subjected him to an assault so vicious and sustained that Mr Wright had no chance of defending himself. Wyard was seen to kick Mr Wright full force to his head as he lay unconscious on the ground.
“The attack was witnessed by a number of people who were shocked by the level of violence used by Wyard and Wootton. Some tried to stop the attack, others informed the police, and some gave first aid to Mr Wright.
“The evidence provided by these witnesses was vital to the prosecution’s case and I thank them all for their contribution.
“What has happened to Mr Wright cannot be undone, and his family feel the deep loss of their father, brother, uncle, and grandfather.
“Now that Wyard and Wootton are beginning long jail sentences, which is the least their actions deserve, I hope that Mr Wright’s family are assured that the public will be protected from these two defendants for many years to come, and feel some sense of justice.”
Mr Wright’s family issued a statement which said: “We are devastated by this life changing event. It puts things that are trivial into perspective.
“Nothing can bring Keith back, but we thank all the witnesses who have helped us get some sense of justice. We also thank the police, legal team, the victim support, and staff at York District Hospital and Leeds General Infirmary who cared for Keith before he died.
“Keith was a private man who kept himself to himself. He was born and bred in York.
“He lived alone in Acomb, but his daughter, grandchildren, sister, two brothers, nieces and nephews all live locally.
“Keith enjoyed listening to music, and kept himself smart. He had a good sense of humour. We miss him.”