Elona Green, 38, of Watery Lane, Ashton-On-Ribble, Preston, was described as being "like a raging bull" by her victim, who suffered a puncture wound to the back of his neck.
She and her boyfriend were then seriously assaulted and 'came off worse', Preston Crown Court heard.
Green admits causing actual bodily harm to David Crossett on September 12, 2019, on the basis it happened after a disagreement between several residents, including her boyfriend and another man.
The victim said he went to intervene after hearing the disturbance, and could hear one neighbour, Mark Paton, and his partner shouting: " Stand on their hands, stand on their hands."
He said there were "arms everywhere" and everything was happening quickly.
Elona Green approached Paton on the stairwell and shouted: " You're not doing that to my boyfriend and getting away with it."
In a statement Mr Crossett - who is now wanted by police for something else - added: " I'll be honest, I put my hands up and tried to push her to keep her away from him.
"I was stuck in the middle.
"I didn't see her try and hit me.
"I've been stabbed before and I know what it feels like - as soon as it was in I knew."
Prosecuting, Richard Archer said Green had given a basis of plea saying she had been "very upset, angry, frightened and in pain and wasn't thinking straight".
Green has 26 convictions for 42 offences but defending, Wayne Jackson said she had been out of trouble since serving a jail term in 2016 and had decided to sort her life out.
She has moved from the flats and is on a methadone prescription.
Suspending her nine month jail term for 18 months, Judge David Potter said: "You were clearly seen on CCTV to come out into the corridor with a potato peeler which you then use to stab twice the back of one of those two men.
"He felt immediate pain in his back and discovered that he had sustained a wound with that potato peeler.
"What's clear from the CCTV is both you and your partner were then subjected to a very violent assault in which you and your partner were struck repeatedly and I'm satisfied you were to sustain a serious injury, probably in excess of the injury occasioned to Mr Crossett.
"You needed two stitches to close the wound inflicted with the implement."
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