The 23-year-old alleged victim was walking from Flemington Station through Airey Park in Homebush, western Sydney, about 11.15pm on Friday, September 18.
There, she was stopped by a man unknown to her, police said.
The man allegedly restrained the woman and dragged her into nearby bushland, where he sexually assaulted her.
Jesse Lee Hardy, 27, was arrested at a home in Padstow, about 13 km from the park, on Thursday morning.
Detective Superintendent Virginia Gorman on Friday said the alleged attack appeared a ''cross between'' opportunism and planning.
"I believe he was planning to do it but the opportunity just happened to arrive at that time," she alleged.
''It wasn't as simple as planning and targeting that particular female, but he was working alone."
Speaking to the alleged attack, and a separate spate of alleged assaults in Sydney, the detective said she could not imagine anything worse.
''A home invasion … being knocked down in the street, is a woman's fear. It should be every person's fear,'' she said.
''That kind of violence against you randomly in the street … there's physical injuries and there's mental injuries.''
The detective said the victim took a couple of days to report the alleged attack to police, which she said was common for non-English speaking victims of sexual violence.
''The fear that comes with that kind of activity means that they sometimes don't report,'' she said.
Police launched an investigation when the alleged victim reported the incident at a police station.
Police raided a home in Padstow about 8.50am on Thursday, arresting Hardy and seizing several items for forensic examination.
He was charged with aggravated sex assault - inflicting actual bodily harm, intentionally choking without consent, taking a person with intent to commit a serious indictable offence, and stalking/intimidating with intent to cause fear of physical harm.
Hardy did not appear in Blacktown Local Court on Friday and made no application for bail.
He is due to appear via video link at a Burwood Court in November.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
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