A 31-year-old Netherton woman was left badly bruised after being repeatedly punched in the face by her best friend.
Sophie Jenkins lashed out when her friend of 20 years found her giggling and in a state of undress with her boyfriend.
Prosecutor Alka Brigue told Wolverhampton Crown Court 32-year-old Jenkins had been befriended by the victim after finding herself with a string of personal problems and she had been offered accommodation at her home in Crescent Road.
Jenkins was heavily intoxicated and after being found with the victim's boyfriend she rained punches on her face in what was a "completely unprovoked attack."
In a statement the victim later told police: "I was only trying to help her because she was my best friend and she behaved like this."
After being arrested, added Miss Brigue, Jenkins sent a text message to the victim threatening her with violence if she continued with her complaint saying: "The last thing you will see is my face lovely girl."
Judge Michael Challinor told Jenkins it was clear it had been a "sustained" assault on a vulnerable victim who was in her own home.
The judge added: "When you were in drink you attacked her and you punched her several times in the face. Then, after being bailed, you sent the text message.
"This was a deliberate attempt to frighten her into withdrawing her complaint to the police. She must have been terrified because you were making a threat to kill her."
Jenkins, of no fixed address, admitted assault causing actual bodily harm and witness intimidation and she was told by the judge anyone who threatened someone involved in a court case had to know they would go straight to prison.
Sarah Allen, for Jenkins, said her client, who was jailed for a year, had a drink problem and "foolishly and stupidly" she sent the text message after she had been released on bail.
Miss Allen concluded: "She accepts she went too far and she assaulted the friend who was trying to help her.”