Jason John Dinsley has been sentenced to life in prison for murdering young Victorian mother Sharon Siermans while he was on parole.

Parolee killer Jason John Dinsley says he cannot remember how many times he hit Victorian woman Sharon Siermans in the head with a cricket bat while her son was just metres away.

By his own admission, he flipped out and lost control, and decided to punish Ms Siermans for all the rejection in his life.

Dinsley, 30, has been jailed for life for Ms Siermans’ murder but will be eligible for parole after serving a 32-year minimum term.

Victorian Supreme Court Justice Elizabeth Hollingworth on Friday said Dinsley had committed a ferocious and cowardly attack against a defenceless woman in her own home.

She said his crimes were almost as horrific as Jill Meagher’s killer Adrian Ernest Bayley and double murderer Steven James Hunter, who was jailed for life for killing Sarah Cafferkey.

“In general terms, your offending is every bit as terrible as that of the men who killed those two women, although there were some additional aggravating features in those two cases,” she said.

Justice Hollingworth said Dinsley, who was on parole for a home invasion and violent rape committed in 2005, attacked Ms Siermans in a state of long-standing and disproportionate anger.

“You engaged in a sustained, ferocious and cowardly attack against an unarmed, defenceless woman in her own home and in the middle of the night,” she said.

The judge said Dinsley knew Ms Siermans had a child but was recklessly indifferent about whether he would have seen the attack.

Justice Hollingworth said she only set a minimum term for Dinsley, who has 143 prior convictions, because of his early guilty plea and co-operation with police.

Ms Siermans, 29, had been on a single date with Dinsley in January after meeting through a dating website and exchanging text messages, before she severed contact with him, later telling friends he was filthy, had dirty clothes and that she was embarrassed to be seen with him.

Dinsley became enraged as he walked past Ms Siermans’ Ballarat home early on the morning of April 6.

He walked to his Sebastopol home and spent several minutes choosing a weapon, before returning with a cricket bat and breaking in.

When Ms Siermans confronted Dinsley in the kitchen, he started hitting her with the bat and tried to rape her before beating her to die.

At least part of the attack was seen by Ms Siermans’ four-year-old son.

Dinsley stole Ms Siermans’ phone and left without checking on her condition, hiding the bat and his own blood-stained shoes in bins while walking home.

Later that morning, Ms Siermans’ son told his grandmother “there was a big man come last night and he bashed mummy with a baseball bat” and “mummy won’t wake up to give me any breakfast”.

Several members of Ms Siermans’ family cheered as the sentence was handed down in Ballarat.