A fisherman grabbed a Tesco manager by the testicles and refused to let go after being stopped after an £800 shoplifting spree, the High Court heard.
Members of the public had to help release his grip as the victim suffered "extreme pain", prosecutors said.
Details emerged as bail was refused to the man accused of the attack outside the store on Belfast's Newtownbreda Road last week.
Samuel Boyd (37), of Portallo Street in the city, faces charges of going equipped for theft, assault and theft.
It was claimed that he went into Tesco on December 5, took security tags off various goods and put them in bags.
Prosecution barrister Conor Maguire said one of the store managers and security watched him on CCTV throughout the incident.
Boyd then left without paying for the items with a total value of £864. Staff gave chase and tried to restrain him at escalators, the court heard.
Mr Maguire claimed: "He grabbed the manager by the testicles and squeezed hard, refusing to let go.
"This caused the store manager, as he recounted to police, to be in extreme pain."
The judge, Mr Justice Weir, commented: "That sounds credible."
Mr Maguire continued: "Members of the public had to come to his assistance and help in the removal of contact with the store manager."
Boyd was said to have been drunk and wearing four jumpers when arrested.
The court heard that before the incident he was working on a fishing boat out of Portavogie.
Defence counsel Michael Boyd described what happened as "an unfortunate blot on an otherwise more positive landscape".
He confirmed his client intends to plead guilty to the offences, telling the court that the thieving was carried out to get money for house furnishings.
Mr Boyd described the attack on the manager as "an unforgivable way to act" for which the accused wanted to apologise.
Refusing bail due to the risk of reoffending, the judge suggested: "Maybe from the prison he could write a letter to the manager of the Tesco store expressing his regret."