In a separate incident, Ameer Khan was involved in a large-scale disturbance with his brother in which people were attacked with weapons.
Leeds Crown Court heard Khan attacked the shopkeeper on January 2 last year at the store on Shepherds Lane, Chapeltown.
Stephen Littlewood, prosecuting, said Khan and a number of other men confronted the victim in a dispute over a car.
The 30-year-old took out a metal bar and struck him over the head with it a number of times.
The man suffered a fractured cheekbone and bruising to his face and around his eye socket.
Khan carried out the attack when he was on court bail for an offence of affray committed on July 16, 2018.
Khan's brother, Shahid Khan, attacked an employee at a car rental business in Batley.
Mr Littlewood said Shahid punched the man to the head several times after he took offence to a comment made to him.
Shahid left but warned that he would be returning later the same day.
The brothers were then among a large group of men who returned to the area in cars.
The prosecutor said around 20 men "swarmed" the streets around the business.
Some wore balaclavas and carried tools including hammers and metal bars.
A number of men were attacked. One victim was knocked unconscious and another suffered a fractured arm.
Ameer Khan, 30, of Stratford Street, Beeston, pleaded guilty to causing grievous bodily harm and affray.
Shahid Khan, 48, of Clovelly Row, Beeston, pleaded guilty to two counts of affray.
Ms Colley said he was a hard-working family man who does a lot of charity work.
Andrew Dallas, for Shahid, said the defendant had not been in trouble in three years since the incident.
He added that the brothers did not join in the violence during the affray incident but they accepted encouraging others.
Jailing Ameer, Judge Simon Batiste said: "The offending is so serious that only an immediate custodial sentence can be justified."
Shahid was given a 12-month sentence, suspended for two years.
He was also ordered to complete 25 rehabilitation activity requirement days and was made the subject of a curfew order for six months.