A dispute between two traveller families led to violence erupting on a petrol station forecourt.
John Goodwin (40) and his son John Varey (18) armed themselves with baseball bats and attacked Danny Brewer in front of his 13-year-old son.
They then smashed up the car in which Mr Brewer had arrived, causing £1,160 damage.
The victim, from the Market Harborough area, suffered a three-inch cut to his head which needed stitches, as well as bruising to his abdomen and thigh.
The attack took place on the afternoon of July 7, at a petrol station in Market Harborough.
Leicester Crown Court was told the distressing incident had caused Mr Brewer's 13-year-old son to suffer sleepless nights.
Recorder Paul Mann QC said: "This was an appalling piece of disorder in public with the use of weapons, and the travelling community has to know if they choose to take the law into their own hands then they must expect a prison sentence."
Goodwin and Varey, both of Chase Terrace, Burntwood, Staffordshire, admitted unlawful wounding, possessing offensive weapons, namely baseball bats, and causing damage.
Goodwin was jailed for eight months.
Varey, who was 17 at the time, was given a 15 month community order and will have to do 150 hours of unpaid work.
The court heard that Goodwin had already paid more than £1,160 to cover the cost of repairing the damaged car, which belonged to Mr Brewer's daughter.
Outlining the incident, Recorder Mann told the defendants: "It all stems from a dispute between your family and the complainant's family which had clearly been going on for some time and got out of hand.
"Neither side comes out of this with any glory.
"The Crown accept it got to the stage where you, Mr Goodwin, were receiving threatening texts and on social media, including threats to burn your own daughter's face with acid.
"It's a great shame that within the travelling community there's such reluctance to involve the civilian police because, if you had, those complaints and threats could have been dealt with, and it may be it wouldn't have been you two in the dock, but others – because those threats would have been taken seriously by the court.
"Sadly, Mr Goodwin took up the complainant's invitation to sort it between yourselves; it was tacitly agreed there would be a meeting at some point where you'd clash and there would be violence.
"I'm satisfied you are both full of remorse for what you've done, and if you could have your time again you would have treated it differently."
Recorder Mann added: "To some extent I think each side wound up the other.
"I'm prepared to accept there was a great deal of provocation and you (Goodwin) were at your wits' end before you decided to do what you did."
Karen Davenport-Coles, prosecuting, said the victim and his son were putting petrol into a can at Protheroes garage in Northampton Road at 1.45pm when the defendants, armed with baseball bats, unexpectedly arrived in a vehicle, and carried out the attack.
She said the victim had said he did not want any further difficulty, and there had been no more incidents to date.
Barry White, mitigating, said the complainant's daughter had initially made extremely disparaging remarks against Goodwin "which started it all off".
He said: "The complainant was looking for a fight and it was dealt with in completely the wrong way.
"In the travelling community there appears to be a different way of dealing with things."
