Magistrates praised the actions of a witness who they believe may have saved a woman from further injury in an assault which led to a hospital stay.
The man was travelling on a bus between Alnwick and Berwick when he saw the woman being harassed and struck in the face and body by Donald Stone.
He intervened, asking the woman to sit with him at the back of the bus, and in the meantime the driver rang police and the attacker was arrested.
Magistrates in Berwick said they believed the actions of the witness had prevented further possible harm being caused to the woman, and they asked the Crown Prosecution Service and police to pass on their thanks.
Stone, 29, of Cedar Grove, Alnwick, had spent 28 days in custody following his arrest.
The court was told that the woman he assaulted, Jodine Mallaburn, was his former partner.
She was travelling on the bus from Alnwick to Berwick, having previously agreed to meet up with the defendant, but deciding against it.
Stone got onto the bus two stops later and sat beside her.
It was obvious he had been drinking, and he had a bottle of lager in his hand.
During the course of the journey he continually harassed Miss Mallaburn, and on one occasion he struck her in the face.
The witness later told police it was obvious the couple were arguing, but it was only when he saw Stone punch Miss Mallaburn in the stomach that he approached and took her to the back of the bus.
The prosecution said Miss Mallaburn had a history of stomach complaints, and after being hit she had to spend the night in hospital when blood was found in her urine.
Stone was arrested after the bus driver telephoned ahead and they were met by police at the Cat Inn on the A1 at Cheswick.
Stone admitted assault and harassment, after it transpired he had later sent Miss Mallaburn a series of text messages, which were in breach of his bail conditions.
He was sentenced to a two-year community order with the requirement of supervision.
Magistrates also imposed a two year restraining order and a curfew between 7pm and 7am for a period of three months. He must attend a domestic violence programme and complete 100 hours of community pay-back.
Stone must also pay Miss Mallaburn £100 in compensation and court costs of £170.