Daniel Bourne, aged 25, joined Lewis Bethell and another man in attacking the victim outside Robson's Stores in Sundorne Avenue, Shrewsbury, on March 30, 2020.
Shrewsbury Crown Court heard how Bethell, who had his girlfriend in the car, had an argument with her former partner outside the shop, before they drove off.
Bethell then returned with Bourne and the other protagonist in tow, before launching an attack on the victim outside the shop.
CCTV footage was shown to the court of the pair chasing down the victim, before punches and kicks were rained down.
The victim was taken to Royal Shrewsbury Hospital, where he received 12 stitches for a head wound, 10 stitches for a cut to his wrist and five stitches to another wound. He was also told he would require surgery for nerve damage to his wrist.
Bourne, of Springfield Way, Shrewsbury, pleaded guilty to affray. Bethell, also aged 25 and of Crowmere Green, Monkmoor, Shrewsbury, was previously jailed last August for five-and-a-half years for a number of offences including attempted GBH and affray.
Previous convictions racked up by Bourne include possession of an offensive weapon, possession of a knife and battery, for which he spent time in prison.
Bourne's defence advocate insisted that Bethell was the main protagonist, and said Bourne was now "a very different man".
She said: "It is clear that Bethell is the main aggressor. At the time of this offence, he (Bourne) had just been released from prison. He was suffering from PTSD."
She said that Bourne is a painter and decorator with his family's firm.
"He is a very different man to when he committed this offence."
Judge Anthony Lowe handed him an 18-month prison term, suspended for two years. Bourne must also pay £1,200 in court costs, carry out 40 rehabilitation activity days and abide by a curfew from 7.30pm to 5am for the next four months.
The judge told him that if a blow landed in the wrong place he "would have been facing a murder charge". "The injuries are serious," added the judge.
"It is not your first appearance before the court for violence. I am quite satisfied from the pre-sentence report that the remorse you show is genuine."