The Victorian County Court has been told a man raped an 85-year-old woman at a Melbourne train station for a thrill.

Allan Richard Hodson, 65, from Bairnsdale, admitted he raped the pensioner at the Southern Cross train station in January.

He ushered the 85-year-old into a toilet block and attacked her. He then threatened her, telling her he knew where she lived.

In an interview Hodson told police he did it for "just a bit of a thrill".

He pleaded guilty to rape, recklessly causing serious injury and making threats to harm.

The judge told the court Hodson's actions were ferocious and his reasoning spine-chilling.

The prosecutor said the crime was committed in broad daylight against a frail woman and submitted Hodson should be jailed for up to 10 years.

The judge agreed a minimum of eight years seemed appropriate.

He suppressed the details of the attack, ruling the woman had suffered enough.