WARNING: This story contains graphic details that may distress some readers.

The heroic actions of a young girl have been outlined in a Melbourne court, which heard the 10-year-old desperately tried to stop a man stabbing her mother to death.

Graphic details of Monique Leszak's killing were revealed in the Supreme Court of Victoria on Friday, as Sven Lindemann faced a pre-sentence hearing after pleading guilty to murder.

Enraged by a relationship break-up, Lindemann used six knives to stab Ms Leszak 17 times in the kitchen of her home in Melbourne's south-east on May 30, 2023.

The court heard Ms Leszak's daughter repeatedly kicked Lindemann and tried to strip him of the weapons during the incident in the Endeavour Hills house.

Ms Leszak's other child, her daughter's twin brother, was in a nearby room as the murder unfolded.

Prosecutor Kristie Churchill said a neighbour heard screams coming from the home, including from the girl who was heard shouting "leave my mother alone".

During the attack, Lindemann was yelling "you've ruined my life" to Ms Leszak as he stabbed her, using so much force that two of the knives broke.

Ms Churchill said Ms Leszak's daughter rang emergency services and told operators: "Please help me, my mum is dead."

In court, Ms Leszak was described by friends as a loving mother who was loyal to those closest to her.

"Monique was the most selfless, hilarious, beautiful person inside and out," friend Jacqueline Schwarcz said in a victim impact statement.

Ms Schwarcz said she scrubbed the blood from the floor of the murder scene in the aftermath, and now suffered from post-traumatic stress disorder.

Judge rejects claims Lindemann was remorseful

Lindemann, a bodybuilder who was abusing anabolic steroids, began sobbing in the Supreme Court dock as details of his offending were read out on Friday.

"Will the accused sit up," Justice Elizabeth Hollingworth interjected.

"Stop the crocodile tears."

The court was told Lindemann retreated to a bedroom after the domestic violence killing and tried to transfer money out of a bank account, before turning a knife on himself.

He suffered self-inflicted wounds and was hospitalised for two weeks.

The court was told Lindemann was recorded speaking to his parents over the phone from prison, and told his father there were "no excuses" for what he did.

"I only know someone hurt me very, very, very much and ripped my heart out of my body. I just can't have it. I couldn't cope with it," Lindemann was recorded saying.

However Justice Hollingworth rejected claims from Lindemann's barrister Lucinda Thies that the 52-year-old was remorseful for his actions.

"He put his head in his hands, he was shaking (in the dock)… turning it on, apparently for my benefit. It was quite unimpressive and disruptive."

Lindemann faces life in prison

The court was told Ms Leszak and Lindemann met online about a decade ago, and Lindemann had left his wife and two children in South Australia to be with Ms Leszak in 2018.

Ms Churchill said by 2022, friends and family "observed signs of jealousy and conflict in the relationship".

Ms Leszak, a bodybuilding enthusiast, met a man in a Queensland gym in April 2023 and continued to stay in touch with him.

She then told Lindemann that she wanted to end their relationship.

Ms Churchill said Lindemann found out about the Queensland man and left him threatening messages, before verbally abusing Ms Leszak the night before the murder.

The following morning, Lindemann told his employer he wouldn't be coming in and attacked Ms Leszak, punching and strangling her before retrieving the first knife.

Ms Thies said her client had "very good prospects of rehabilitation" and had no prior criminal history.

Lindemann faces a maximum sentence of life in jail for the murder, with Justice Hollingsworth to hand down her sentence at later date.

"Domestic violence abusers and offenders often present one face to the world and one face to their partner," she said.