A Ranby prisoner attacked a guard who mistakenly opened his cell after a search for contraband that had been thrown over the wall, a court heard.
James Dore hit the officer on the right side of his face and continued to punch him, said prosecutor Robert Carr.
“Other staff came and Mr Dore jumped on to the security netting,” said Mr Carr.
The court heard Dore had been escorted back to his cell after several prisoners were searched when a package had been thrown over the wall, on December 20, last year.
The guard was left with a chipped front tooth, bruising to his right eye, swelling to his right temple and a sore jaw.
In a statement, he said the attack had left him in pain and discomfort over Christmas, and his family had been concerned about him returning to work.
Dore was serving “a number of years” in prison after he was convicted of robbery, in 2016, added Mr Carr.
Probation officer Sarah Alderton told the court Dore was released on January 19, and would be on post-sentence supervision until December 2019.
She said he had been engaging well with the probation team, but had violated the terms of his GPS tracking device twice.
Stacey Mightie, mitigating, said: “On the day in question contraband had been thrown into the prison and a number of prisoners had been searched.
“He was upset because he wasn’t involved in the contraband. He said he was manhandled into his cell. He was upset and angry.”
She said he was now living with his father and trying to find work as a welder.
Dore, 21, of Soudan Drive, Nottingham, admitted assault when he appeared at Mansfield Magistrates Court, on Friday.
Magistrates gave him 100 hours of unpaid work for the “unprovoked attack on a prisoner officer who was trying to do his duty”.
He was ordered to pay £200 compensation and £85 costs. No government surcharge was awarded because he owes £1,030 to the courts.