A submissive "slave" asked by a Melbourne dominatrix to beat her boyfriend badly enough that he'd leave town has pleaded guilty to his murder.

Stuart Lindsay Heron, 49, pleaded guilty in the Victorian Supreme Court on Tuesday to the murder of Nicholas Cameron in July 2021.

His plea comes just weeks after dominatrix Heide Victoria Bos, who used the name "Hedonistic Siren" on the fetish website where she met Heron, was jailed for six years and three months for manslaughter.

Heron had been seeing Bos on and off for a time and she asked him to beat Mr Cameron enough that he would leave town and leave her alone.

Instead, it was revealed when she was sentenced, Heron lay in wait in Mr Cameron's apartment complex car park for hours on the night of July 9.

When Mr Cameron went into the car park with his white terrier, Misty, Heron attacked.

He was beaten with a hammer and stabbed in a ferocious attack lasting 11 minutes. Mr Cameron suffered grave injuries and died at the scene.

Neighbours called police, who arrested Heron as he tried to leave.

Heron will face a pre-sentence hearing on August 11.

His barrister said they wanted a neuro-psychological report for the former mechanic, who has an acquired brain injury.