The victim was threatened with a knife and punched during the attack at Exhibition Park in the early hours.
Her attacker is described as of Asian appearance, aged about 25 or 30, of thin build and wearing a grey hoodie.
Northumbria Police has asked anyone who was in the Exhibition Park or Spital Tongues area at the time - about 03:00 BST - to get in touch as they might have vital information.

Nofa Mihlo Rafo arrived in Canada this year as a refugee with four of her six children.
She was separated from her husband and two eldest sons after their town was captured by the so-called Islamic State in 2014.
She learned this week that one missing son is still alive after a relative alerted her to a photo posted online.
Ms Mihlo Rafo learned last Sunday that 12-year-old Emad Mishko Tamo was alive and had been rescued.
She "was jumping, crying at the same time, just happiness", said Hadji Hesso, with the Yazidi Association of Manitoba.
His group, in partnership with the Kurdish Initiative for Refugees, Winnipeg Friends of Israel and the Liberation of Christian and Yazidi Children of Iraq (CYCI), has launched a campaign to reunite the boy with his family.
On Thursday, Canada's federal immigration department said it is aware of the boy's case and noted that the government has committed to bringing up to 1,200 vulnerable Yazidi women and children and other survivors of IS to Canada.
"All Yazidi cases are being expedited," said a department spokeswoman in an email.
Steven Maman, the founder of CYCI, says that all 338 Canadian members of parliament were sent information about the boy.
"Everyone has received an email from us with Emad's story, his mother's identification cards, everything," Mr Maman said.  "It's a moral obligation for us human beings to help her."
There is also a special programme that allows refugees to apply to bring in dependent children within a year of arrival.
Iraqi troops who found the boy posted his image online in hope of finding his family, said Mr Hesso.
The boy's uncle saw the photo, contacted Emad's mother, and met the boy at the hospital where he was being treated for shrapnel and gunshot wounds.
Mr Hesso says the boy is recovering and now with his uncle in a camp in Iraq.
Ms Mihlo Rafo and her children are all members of the persecuted religious Yazidi minority. They were rounded up by IS jihadists in their town of Sinjar in northern Iraq and held captive for two years.  She eventually managed to escape to a refugee camp with four of her children.
A man who raped a woman in a Newcastle park is being sought by police.
[NEXT_CONCEPT]
Canada says it is aware of the case of a Yazidi boy recently rescued by Iraqi forces whose mother is in Winnipeg.