The attacker ambushed the terrified victim, 22, after breaking into her house in Old Trafford.
He threatened the woman by holding a knife to her face and demanded she handed over money.
Then the man brutally raped her before escaping the scene.
The horrific incident took place at 7.30pm on Saturday evening.
Greater Manchester Police have launched a manhunt to trace the violent attacker.
The suspect is described as in his 20s to 30s, white and of medium build.
He was wearing a dark hooded top or coat and dark coloured trousers at the time of the incident.
Detective Inspector Carl Gilbert described the attack as "shocking" and "terrifying".
He said: “This is an absolutely shocking incident and one that is sure to cause much concern to anybody who hears about what has happened.
“This man forced his way into the address and subjected his victim to a brutal and terrifying rape."
Now the woman is in the care of specially trained cops.
It is believed the victim did not know her attacker.
The detective added: "We have a team of specially trained officers working to investigate and providing her with support.
“The attacker was completely unknown to the woman and I would ask the people of Old Trafford to please contact the investigation team if they believe they may have seen anything suspicious yesterday evening or in the hours following the rape.”
Call cops on 0161 856 7655 or Crimestoppers 0800 555 111 anonymously.