A carer punched a disabled man to the ground and stamped on his head after accusing him of being a police informer.
Mark Bradley snapped and attacked his 61-year-old friend in his own home in frustration after a failing a job interview.
Bradley, 51, was locked up for two-and-a-half years over the incident at the flat he shared with the victim in Pontefract.
Leeds Crown Court heard Bradley had been close friends with the victim, who suffers with mobility problems, and became his carer after moving into his home.
The attack took place on March 21 last year after Bradley came home angry after an unsuccessful job interview.
Michael Smith, prosecuting, said Bradley said to the victim that the police were to blame for him not getting the job.
The two men rowed and the victim told Bradley he needed to get a job as he owed him money.
Bradley punched the older man several times to the face, knocking him to the ground.
He then kicked him to the face and body and stamped on his head.
The prosecutor said: "He said he would kill him and accused him of being a police informer."
Bradley continued to kick the man in the back to stop him getting up.
The victim managed to get out of the property and flagged down a passing driver who helped him.
He suffered blurred vision from the attack as well as bruising to his face and body.
Bradley, of Banks Avenue, Pontefract, was arrested and initially denied the attack.
He pleaded guilty to inflicting grievous bodily harm.
Bradley has three previous convictions for violence.
Anthony Sugare, mitigating, said: "This defendant has difficulties with his emotions and from time to time exhibits frustration as he did on this occasion."
Mr Sugare said Bradley lost his temper when the victim refused to listen to his explanation for why he had not got the job.
He added that Bradley had since managed to get a job as business development consultant but would lose his employment if he was jailed.
Deputy Judge Robert Moore said: "It was a sustained attack on a vulnerable man. You know that nothing other than an immediate sentence can be justified."