The victim, who was 17 at the time, was assaulted in Rose Lane, following a verbal altercation between two groups of young people during the early evening of Thursday 6 June 2019.
He suffered serious head injuries, leaving him with long-term brain damage which requires ongoing treatment.
Following an investigation by the Kent and Essex Serious Crime Directorate, ten people were charged in connection with the attack.
A jury unanimously found Jack Barron, 17, from Longbury Drive, Orpington and Luke Fogorolli, of Sturry Road, Canterbury, guilty of grievous bodily harm with intent following a trial at Canterbury Crown Court.
Barron was also found guilty of violent disorder. Fogorolli had already pleaded guilty at an earlier hearing to violent disorder.
The court had heard that, shortly before the attack, Barron had gathered bricks into a bag, which he swung at the victim’s head during the assault, sending him to the ground. Eighteen-year-old Fogorolli joined in by kicking the victim’s head, leaving him injured as they ran away. Witnesses said they had heard the two assailants boasting and laughing after the assault.
The two defendants were sentenced on Friday 15 January 2021, Barron to six years in a young offender institution. Fogorolli, who was also sentenced for a separate incident relating to possessing drugs with intent to supply and possession of an offensive weapon, received a total custodial sentence of six-and-a-half years.
Detective Inspector Ross Gurden said: ‘There can be no doubt of the part that was played by these two offenders in an assault which led to a teenager being left with life-changing injuries.
‘They may have run from the scene after the attack on that fateful day, but ultimately they will never be able to escape the consequences of their actions and I am pleased the court recognised the severity of their crimes.’
The remaining eight suspects are due to appear in court at a later date.