Shahram Husseini, 26, had offered to help his 24-year-old victim find her friends after he discovered her walking by herself in the town centre.
But instead he lured her back to his home and raped her on the sofa, Cambridge Crown Court heard.
Husseini, of Railway Road, Wisbech, was found guilty of rape on an 11 to one majority verdict after a six-day trial. The jury took more than eight hours to reach this afternoon’s decision.
Sentencing Husseini, Judge Anthony Bate said: “I accept that you did not set out to commit any crime against her. However, she was clearly the worse for wear for drink and we could see the extent of that from the CCTV of Norfolk Street.
“In the time you spent together your intentions changed from helping her to meet up with her ex-boyfriend to instead taking her to your own home. Having got her there, you raped this young lady.”
Judge Bate added: “She thought she would be safe with you, but she wasn’t.”
Husseini committed the crime in March this year – months after fleeing his native Kurdistan to stay with friends in Wisbech.
The court heard that after their “chance encounter” on a Wisbech street, Husseini took the woman back to his home and had unprotected sex with her.
She managed to leave the property in the early hours of the morning, when she found her friends and reported what had happened to the police. An investigation was launched and Husseini was identified as a suspect straight away.
Husseini wept in the dock as Angela Rafferty, mitigating, told the court that he had “never seen any happiness in his life”. His father was killed in the war in Iraq while his mother had died in a car crash.
Ms Rafferty said Husseini had not used violence and that he lacked a “certain degree” of education and cultural awareness.
“This clearly started as a chance meeting,” she said. “This was not a situation where he went out searching for a woman to assault.”
Ms Rafferty added: “He has found the experience of prison very, very difficult.
“He has seen a lot of violence there and he has seen a lot of violence in his life. At times, he says he feels suicidal.”
Husseini was sentenced to six years, of which he will serve half in custody, and was placed on the sex offenders’ register indefinitely.
Upon his release from prison he will be considered for deportation.