The victim was slashed on the arm when violence erupted at King Kebab, in Beeston, Leeds.
A court was shown CCTV footage of the disturbance outside the takeaway on Tempest Road.
The stab victim's son was also hit over the head with a metal bar when he went to help his father as he was attacked by brothers Sajid and Abid Hussain.
Jon Close, prosecuting, told Leeds Crown Court heard how the incident happened on June 8, 2017.
He said: "At 9.10pm Sajid Hussain arrived angry and upset that his two children, who had been in takeaway, had not yet been served."
Sajid, 35, argued with the kebab shop owner before leaving but returned at 11.20pm with his brother.
Mr Close said Abid punched the victim to the head.
He added: "He then felt a sharp pain to his right arm.
"He formed the view that he had been stabbed and that the blow had been struck by Abid."
The court heard the owner's son then went to help his father and took a metal bar out into the street.
Mr Close said the son dropped the metal bar as he fought with Sajid.
Abid, 39, then picked up the bar and hit him over the head with it.
The kebab shop owner had to undergo surgery after suffering a "gaping wound" to his arm.
Police later found a pocket knife in the grounds of a church opposite the shop. It contained the victim's DNA.
Abid, of Stratford Terrace, Beeston, pleaded guilty to unlawful wounding, assault occasioning actual bodily harm and having an offensive weapon.
He was jailed for 18 months.
Jeremy Hill-Baker, for Abid, said his client accepted going to the scene to help his brother and being in possession of the knife.
He added that Abid had not been the "instigator" of the attack.
Mr Hill-Baker said the father-of-five had not been in trouble since the incident and did "great good" in his local community.
Sajid, also of Stratford Terrace, Beeston, pleaded guilty to battery.
He was given a three-month prison sentence, suspended for 12 months.
Imran Khan, for Sajid, said his client was of previous good character and had admitted the offences at an early stage.
Jailing Abid, Recorder Dafydd Enoch, QC, said: "This is exactly what the public are angry about - people going about with knives."
He added: "It all happened in the street in front of the general public.
"It is just the kind of thing that society wants to stamp out."