An off-duty policeman celebrating his 21st birthday was seriously hurt after he stepped in to stop trouble.
Neil Tyldesley intervened when Misbah Malik was being aggressive in Bristol city centre.
Instead of complying, Malik punched him to the ground and he sustained a broken jaw which could have implications for the rest of his life, Bristol Crown Court heard on December 20.
Malik was due to be released from prison early on December 28 after serving a two-year jail term for supplying Class A drugs.
But the 22-year-old, of no fixed address, pleaded guilty to inflicting grievous bodily harm (GBH) in April – around the same time as his drugs supply to undercover police.
Judge Mark Horton jailed him for a year, which will start after his current prison sentence is completed.
The judge told him: “I have to sentence you for an extremely unpleasant and serious attack on an innocent young man, at 4am, in the presence of other members of the public and in the presence of his partner.
“You knocked him down, he clearly lost consciousness and there were grave fears the end result would be much more serious than it eventually was.”
Gregory Gordon, prosecuting, said Malik was seen around 4am in Queens Road, outside the university building, where women were telling him to go away.
The court heard When Mr Tyldesley’s friend, Tom Curry, tried to calm him down, Malik threw a kebab at him, took his coat off and walked towards him.
Mr Gregory said: “Mr Tyldesley stepped in.
“He tried to get the defendant to calm down, using open palms.
“The defendant punched him once to the side of his head and he fell to the floor instantly unconcious.”
The court was told Malik then took his own belt off and tried, but failed, to hit people at the scene before fleeing.
He was arrested some two weeks later and was identified via a video identity parade.
Mr Tyldesley sustained a broken jaw which required corrective surgery, the court heard.
It was said he suffered a permanent misplacement of his teeth and could endure permanent pain.
Malik, a new father who appeared via video link from HMP Portland, was given leave to speak to the judge.
He said: “Your Honour, I just wanted to say I’m so sorry to the victim and what I’ve done to him, and no-one should go through that.”
Tabitha Macfarlane, defending, said her client was a bright, articulate young man from a very pro-social family and had expressed remorse.
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