Good Samaritans came to the rescue of a woman viciously assaulted and raped while walking to her car in Northbridge in the early hours of Australia Day.

The victim, in her 20s, was walking along Aberdeen Street around 4.20am Sunday when she was approached by a man who asked her for money.

When she refused to hand over cash, he allegedly attacked her both physically and sexually, causing serious injuries to her head, face and neck.

But police said the onslaught, which took place outside an apartment complex near the Pier Street intersection, may have been even worse were it not for nearby residents and members of the public who rushed to the aid of the victim when they heard her screams.

"Without their intervention the woman could have been more seriously injured," a police spokesperson said.

The victim was taken to Royal Perth Hospital but was discharged Sunday.

Kellerberin man Dillon Smith, 27, has been charged over the brutal attack.

He did not apply for bail when briefly fronting Perth Magistrate’s Court yesterday afternoon.

Kim Jarvis, a cleaner at the apartment building, said she had been left shaken by news of the alleged rape.

“It's disgusting. I mean we should be able to go out and come home whenever we feel like it without being attacked,” she said.

Nearby business owner Muhammad Taimoor said he had noticed a heavy police presence on Aberdeen Street on Sunday morning.

“I'm just speechless... it's like really not good,” he said.

Wearing a red shirt and jeans, Mr Smith entered court with a noticeable limp.

No details of the the alleged assault were read out in court and Mr Smith did not make a bail application.

He spoke only to confirm he understood he was being remanded in custody until his next court appearance at Perth Magistrate’s Court on February 21.

His charges include four counts of aggravated sexual penetration without consent and two counts of aggravated indecent assault, as well as one count each of assault occasioning bodily harm and aggravated assault with intent to rob.