The Langwarrin man, 30, handed himself into police on Friday, hours after the sexual crimes squad released CCTV images of a suspect in a public plea for information.

Detectives said the victim, a 25-year-old woman, had been left "extremely traumatised" after the vicious attack outside the Pint on Punt hotel in Windsor on Monday.

The woman, who earlier had been having drinks with her family, was sitting alone outside the pub when she was approached by a stranger about 12.40am.

The man had been walking south along Punt Road and stopped to talk to the woman for about 20 minutes, before the pair started walking together along Peel Street.

But the conversation soured about 50 metres down the road and the pair started arguing when they stopped outside a house.

Police said the man forced the woman to the ground, where she was "seriously sexually assaulted".

The attack lasted five minutes, police said.

The man ran off, leaving the woman with minor injuries. There were no witnesses to the attack.

Detective Senior Constable Josh Tink said the attack appeared to be "opportunistic", with no links to other unsolved cases.

"The victim is extremely traumatised after the incident," he said. "She's in the care of her family and friends at the moment."