Police are recommending several charges against the man, who they say has a criminal record from outside B.C.
An outstanding warrant for his arrest was issued in London, Ont., for failing to comply with a probation order.
The woman, who witnesses say was covered in blood following the attack, is recovering in hospital from serious injuries, according to police.
Investigators held the crime scene overnight and are back at work this morning combing the area for clues and talking to potential witnesses.
Police say a man armed with a weapon barged into the woman's house in the 800 block of Union Street just after 12 p.m. PT Thursday, tied her up and sexually assaulted her.
Good Samaritans to the rescue
Another man heard the woman's screams and intervened, getting into a fight with the alleged assailant, police said. Several other people rushed to the aid of the woman.
The struggle spilled out onto the street, and they held the suspect until police arrived.
While police discourage witnesses from intervening, they described the man who rushed to the woman's aid as a "hero" and a good Samaritan.
Plans are now in the works for a prayer walk for the woman as well as recognition for those who helped her.
Residents have started a coffee fund for her rescuers at the Union Market cafe, a local hangout.
Pete Fry says the community is doing what it can.
"We're all sick with concern for the young woman who was assaulted," he said. "I think everyone, the entire community's hearts are out for her and we really want to do what we can to support her."
Vancouver police Const. Brian Montague says the attacker was a stranger and the assault appeared to be entirely random.
Police said he recently moved to Vancouver and they have had previous contact with him.