Mohammed Gulzareen, 38, admitted putting schoolboy Imaan Hussain, then 15, into a headlock and savagely biting his ear after he saw his son, who suffers from a rare blood disorder, involved in a schoolyard fight.
Gulzareen, who was waiting in his car to pick up his own son from the school, ran into the fight when he saw his son bleeding on the floor.
Seeing his son surrounded by a group of boys, Gulzareen panicked and dived into the fight, Bradford Crown Court heard.
Gerald Hendron QC, prosecuting said the incident took place outside the gates of Bingley Grammar School on June 15, 2016.
Imaan was sitting on a bench opposite the school gates having just finished a chemistry GCSE exam.
Mr Hendron said: “The complainant’s testimony says that he saw a commotion outside of the gates.
“There were two groups of students involved and he didn’t know what was going on at first.
“But then he saw one of his friends being thrown to the ground and ran over to intervene.
“The defendant’s son was involved in the group that he approached. He was knocked to the ground and a witness saw blood around his teeth.
“Witnesses said the defendant’s son was pushed into the path of oncoming traffic and was surrounded and targeted by members of the group.”
Bradford Crown Court heard Gulzareen’s son suffers from a rare blood disorder called Factor 13, which stops his blood from clotting. Seeing his son in trouble, Gulzareen rush to help him.
Mr Hendron said: “The complainant told police he had been pushed into the defendant by other boys.
“The defendant suddenly went on the offensive at this group that was surrounding him.
“The complainant was put in a headlock and later described the most horrific pain in his left ear.”
Imaan suffered a 3cm wound to the back of his left ear lobe. It took surgeons three hours to put Imaan’s ear back together using 28 stitches and a skin graft from the youngster’s leg.
The court heard Imaan, now 17, from Bingley, missed three more GCSE exams because of the attack and felt he could not attend the school prom.
Gulzareen, from Cottingley, pleaded guilty to one count of grievous bodily harm on September 25, 2017.
In mitigation, Nick Barker QC pointed out the defendant did not act with pre meditation or in excessive self defence and this was wholly out of character.
Mr Barker said: “The group confronting him were quite capable of presenting a great threat to him.
“He was an ordinary, hard working man who found himself in an extraordinary situation brought about by others and not himself.
“He responded wrongly and rashly but it was while he was under great duress.”
Sentencing, Judge Durham Hall QC said: “You are 38-years-old. Until the fateful events of the June 15, 2016, you were a man of impeccable character.
“Something happened to cause you to inflict a nasty wound upon a fellow student of your son at Bingley Grammar School.
“But inflict that wound you clearly did on the complainant, a 15-year-old boy.
“Your son suffers from a rare blood disorder in which his clotting mechanism is severely compromised. If he bleeds it is far worse than for the rest of us.
“The crown accepts you intervened to break up the fight and protect your son which any normal father would do.
“It is accepted that the complainant was pushed into you but you would not know that. You were surrounded when you put him into a headlock but then you bit his ear quite savagely.
“I take the view that I must be right to suspend this sentence. You are a credit to society.
“Locking you up would cause a source of grievance to the public but more importantly would have a terrible effect on your family.
“You must try as all of us who are parents and grandparents must to measure your response even when you are confronted by the most distressing of circumstances.”
Mohammed Gulzareen was jailed for 10 months, suspended for 12 months. Gulzareen, who works in a take-away and appeared in court with an interpreter, will not have to pay any compensation to his victim.
Judge Hall said: “Any compensation payments would not be appropriate due to the defendant’s financial situation. However, the usual victim surcharge will need to be paid.”