The defrocked priest is considered one of Australia's worst paedophiles and he admitted to a family member his victims numbered in the hundreds.

Ridsdale was moved from parish to parish within the Ballarat Diocese, starting at St Alipius in Ballarat, before serving at Warrnambool, Inglewood, Apollo Bay, Edenhope and Mortlake.

A directions hearing in the Victorian Supreme Court on Friday scheduled a 10-day trial to start on January 29.

After that hearing Judy Courtin Legal released a statement on behalf of the Ridsdale abuse victim who has issued a writ against Bishop Paul Bird for the Diocese of Ballarat.

"We are pleased that the Catholic Church has admitted liability for the sexual abuse of our client by Gerald Ridsdale," the statement said.

"We believe this is the first time in Victoria that the Catholic Church has admitted that it failed to protect a victim of child sexual abuse and that it is therefore legally liable.

"Our client now looks forward to an assessment of the damages he is owed by the church."

The victim said it had taken more than nine months and a ruling by a Supreme Court judge to get the church to admit what it actually admitted to the Royal Commission back in July 2016.

"So, I'm glad they've finally seen sense," he said.

"But it shouldn't have to be this hard, especially given that the Bishop of Ballarat has publicly said how much compassion the church has for victims."

Judy Courtin Legal said it would make no further comment as the matter was before the court.

Legal sources said the admission of liability was a game-changer for clergy abuse victims.

The writ plaintiff was raped by Ridsdale in a confessional box at Mortlake during April 1982.

When the writ was issued during February last year, there were two defendants - represented by the present Bishop of Ballarat Paul Bird, on behalf of the estate of the late Bishop O'Collins and the estate of the late Bishop Mulkearns.

As those defendants did not admit they were liable for the victim's abuse by Ridsdale, the victim sought to file an amended statement of claim that incorporated additional material needed to help prove liability.

It also added the Diocese of Ballarat and the Diocese's Roman Catholic Trust Corporation as defendants.

The proposed amendments were opposed by the existing defendants and the matter was heard by Justice Michael McDonald on May 6 this year.

On May 29 Justice McDonald granted leave to the plaintiff to file the amended statement of claim.

Last month the four defendants served their defences to the amended statement of claim.

In those defences Bishop Bird, on behalf of the estate of the late Bishop Mulkearns, admitted that Bishop Mulkearns breached his duty of care to the victim because the bishop knew in 1975 about a complaint of Ridsdale sexually abusing a child at Inglewood.

The Diocese of Ballarat also admits that they failed to take any reasonable steps to protect the victim from Ridsdale after they knew about the Inglewood complaint.