Tariq Jahan, 46, was found guilty of inflicting grievous bodily harm following a four-day trial at Birmingham Crown Court.
Jurors heard that he punched 34-year-old Sajjid Ali after the pair got into an argument in Handsworth, Birmingham, on July 6 last year.
The attack happened a month before Jahan won national acclaim for an impassioned appeal for peace after his 21-year-old son Haroon was killed during disorder in the Winson Green area of Birmingham.
Judge William Davis QC said: “People who break people’s jaws in this kind of mindless violence normally go to prison but I take a view that because of his extraordinary position it is right to suspend sentence.”
Addressing Jahan, he added: “Ordinarily this would mean that you would go to prison for 12 months but this all happened last July and in August, as everybody in this court knows, you suffered the loss of one of your sons, which was desperate in itself.
“But more particularly, in the aftermath of this loss you took steps which in my judgment... probably prevented really serious disorder continuing in Birmingham.”
The judge, who said he had sentenced many people for riot-related crimes since last summer, described Jahan’s actions as “a genuine public service”.
Jahan’s sentence was suspended for two years and he was ordered to complete 100 hours of unpaid work. He was also told to pay £1,000 compensation to Mr Ali within 12 months.
The court heard that Mr Ali was taken to hospital by his manager and treated for two fractures to his jaw after the altercation outside his workplace in Factory Road. He also lost two teeth and had bruises to the left temple area of his face.
He told the jury Jahan had attacked him after accusing him of staring at his wife, who was in the car.