Cortney Batchelor, 21, was out with friends in the early hours of August 23, 2015 when he clashed with 24-year-old Tomas Juska at Club Cookies nightclub on Court Drive.
Outside the club, Batchelor threw a single punch at Lithuanian Mr Juska, who fell and hit his head on the pavement.
Mr Juska died in hospital the next day and Batchelor, of Paisley Close in Luton, was soon apprehended by police.
Today, Batchelor was sentenced to four years in prison at Luton Crown Court.
Jailing him, Judge Richard Foster said: “What you could have done was go home in the car which was just a few yards away.
“If you had done so he would still be alive and you would have not been facing this.
“Every human life has a value and as a result of your conduct (Juska) will not get to live his.”
Judge Foster described Tomas Juska as a “gregarious” man with a “wide social circle” who “was a threat to no-one but himself”.
Batchelor, who must serve half his sentence in jail, was denied credit for remorse.
Judge Foster added: “In your case you are still in denial and pertain that you were acting in self defence.
“You explained how you hit him with an uppercut...I regret I cannot find any evidence of remorse.”
In a victim impact statement Mr Juska’s brother Vaidas said that the tragedy has had a devastating effect on his family.
He said: “When I think about him I feel a mix of upset and anger.
“Not anger at who punched him but anger at the fact he is no longer with us.
“I do not blame the person who punched him because I realise that it takes two people to be involved in something like this but it doesn’t stop me thinking that what happened isn’t fair and that it isn’t fair that Tomas was killed in such a way.
Vaidas added: “I still find myself feeling disbelief that Tomas is dead and that I won’t see him again.
“Sometimes I think he has just gone away travelling and that I will see him when he gets back but then I realise he isn’t coming back and it hurts.
“I don’t think myself or my family will ever get over what has happened.”
Batchelor was previously convicted of manslaughter on April 18 following a trial by jury at the same court.
The tragic circumstances surrounding the case were covered in the episode ‘One Punch’ of Channel 4 documentary series 24 Hours in Police Custody.
The episode showed footage of paramedics attending Mr Juska at Court Drive and followed the story right up to Batchelor’s conviction for manslaughter last month.
Following the conclusion of the case detective inspector Fraser Wylie, of the Beds, Herts and Cambs major crime unit, said: “Although Batchelor may not have intended to kill someone, you cannot escape the fact that a person died as a direct result of his actions on that night, and I am pleased that justice has been done for Tomas.
“Batchelor attempted to hide behind the claim of self-defence which has not stood up to examination through this trial, so I am glad that he was found guilty and will face time behind bars.
“What may seem like an innocuous punch can have a devastating impact, so we hope that this makes people think twice before resorting to violence. Not only has Batchelor taken a life, he has also severely impacted on his own – as well as the lives of both him and Tomas’ friends and family members.”
DI Wylie added: “I hope this will act as a lesson to other young people - it only takes one second and one punch to change the lives of so many people for the worse.