Minor, 25, was among three people who confronted the man when he arrived at a southeast Brisbane unit in November 2020, telling him "we set you up, dog".
Despite the man's offer to cut ties and never see her again, the woman said it was "too late" before stabbing him in the shoulder and twisting the blade.
In response, the man laughed and said he was leaving the Alexandra Hills apartment - then Minor pounced.
Grabbing him from behind, Minor sliced the man's throat with a knife, severing his windpipe and jugular vein.
"The group told the complainant 'you're dead dog'," crown prosecutor Steven Dickson told the Supreme Court on Tuesday.
The man was not only able to leave the apartment but after "some trouble" drove himself to hospital before telling police about the attack a couple of days later.
There had been seething tensions between the man and the woman for some time, the court heard.
"The key cause of the animosity was the complainant taking a photo of ... (the woman) while she was smoking methamphetamine," Mr Dickson said.
"The offending is revenge for what can only be described as petty reasons."
The "brutal, malicious" attack was described in detail as secondary school children entered the courtroom to observe, prompting stares from a heavily tattooed, mohawked Minor.
"The act of slashing someone's neck from behind is exceptionally dangerous, it could easily have resulted in ... death," Mr Dickson said.
Justice Peter Callaghan interjected: "It's more than dangerous, there's something particularly sinister about that action ... something so calculated, so premeditated, so targeted (about) holding a man while you slash his throat."
But when Mr Dickson suggested that the students leave because of the "serious matter", Justice Callaghan said: "No, they have seen worse than this on any Netflix series".
Minor was left extremely angry after suffering domestic violence at a young age from one of his stepfathers, and had been in and out of custody since 13, defence barrister Chris Minnery said.
His drug use had exacerbated feelings of hurt, shame and helplessnes, Mr Minnery said.
Minor lacked support outside prison with his mother also struggling with drug addiction, the court heard.
While in prison, Minor gave himself extensive facial tattoos.
"He wants to look fierce so no one else will attack him," Mr Minnery said.
A psychologist's report tendered to the court diagnosed Minor as "institutionalised".
"He feels safer in custody," Mr Minnery said.
Minor pleaded guilty to one count each of wounding and malicious act with intent and will be sentenced on Friday.
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