Two teenagers are in custody for beating a barrister so badly he was left with permanent brain damage.
Hayward pleaded guilty to inflicting grievous bodily harm on Mr Wareing
Peter Wareing, 42, who is married with three young sons, was walking home along Churchill Road, Poole, in Dorset in June, 2005, when he was set upon.
Bournemouth Crown Court heard that Mr Wareing was lucky to survive.
Daniel Hayward, 19, was sent to a Young Offenders' institution for 18 months and Martin Warren, 17, was given an 18-month detention and training order.
Hayward had pleaded guilty to "unlawfully and maliciously" inflicting grievous bodily harm on Mr Wareing. Warren had pleaded guilty to the same charge and also admitted assaulting Mr Andrews causing him actual bodily harm (ABH).
Hayward and Warren, both from Poole, were with a gang of about seven youths who had been drinking at a birthday party when they picked a fight with Mr Wareing and his friends.
Mr Wareing was walking with two friends just before midnight after attending a barbecue.
Prosecuting Tim Coombes told Bournemouth Crown Court: "Nothing that Mr Wareing had done was in any way provocative or deserving of the injuries he was about to sustain."
Warren punched Mr Wareing, he fell to the floor but got back up.
Hayward then knocked him back down to the ground with a second punch and Mr Wareing hit his head on the cobblestones causing severe brain injuries.
Mr Coombes said: "It was thought in the first instance that he would not survive his injuries.
"He had qualified and hoped to practise at the bar and that career is now lost to him."
Judge John Beashel told the pair: "You were looking for trouble and prepared to use any excuse to visit violence on whoever came by.
"It's the callousness of this that is so chilling especially in your case Hayward.
"It seems you don't seem to care that others have been blighted by your gratuitous violence."