Alex Griffith and Alfie Clarke attacked the victims, who were unknown to them, following a night out in Dartford in July 2019.
Both men were sentenced at Woolwich Crown Court on Tuesday 13 April 2021.
The assault took place in Hythe Street, Dartford, at around 3.45am on Friday 19 July, shortly after Griffith and Clarke left a nightclub.
While loitering in the town centre, the offenders became aggressive towards two men who were sitting on a bench eating a kebab.
Upon being approached by Griffith and Clarke both victims, who are in their 30s, said they did not want any trouble. In response, Griffith threw several punches at one of the men and they fell to the floor after one of the strikes connected with the back of their head.
At the same time, Clarke punched the second victim in the face. He then joined Griffith in repeatedly kicking the first victim in the head while he lay motionless on the floor.
An onlooker intervened and both offenders briefly stepped away.
As two members of the public applied first aid to the man who had been repeatedly kicked, Griffith and Clarke turned their attention to the second victim once again.
They threw him to the floor and kicked him before running away when they noticed blue lights flashing nearby.
The first victim was left unconscious with a jaw that had been broken in two places, in addition to a broken nose, and was treated at a London hospital. The second victim was treated at a local hospital for bruising to their face.
Following a review of CCTV, and after speaking with numerous witnesses, the offenders had been identified and detained within a month.
Griffith, 20, of Pacific Close, Swanscombe, was sentenced to five years and six months’ imprisonment after admitting grievous bodily harm with intent and actual bodily harm.
He also admitted a further charge of actual bodily harm following a similar assault which took place in Dartford High Street on 13 October 2018.
Clarke, 19, of Mildred Close, Dartford, admitted grievous bodily harm with intent and actual bodily harm. He was sentenced to four years and nine months’ imprisonment.
Detective Constable Martin Stevens, Kent Police’s investigating officer for the case, said: ‘Griffith and Clarke have both demonstrated a clear propensity for violence and left a man with serious injuries.
‘In addition to their offending being senseless and unprovoked, their decision to repeatedly kick someone as they lay on the floor injured, unconscious and unable to defend themselves, is beyond cowardly.
‘There can be no doubt they were intent on inflicting as much harm as possible and it is only down to good fortune that no one was left with more debilitating, or fatal, injuries.
‘It is entirely appropriate that they have received custodial sentences and I hope this result provides the victims with a sense of closure.’