Osama Alkhair was interrupted as he tried to rape a woman who was passed out under the influence of drink and drugs on December 29 last year.
The woman was naked from the waist down and Alkhair was in the process of removing his own trousers when a man came across them and intervened.
Alkhair, an asylum seeker with settled status who was living in a hostel in Croydon, denied attempted rape but was found guilty by a jury on Friday, September 12.
At Croydon Crown Court on Monday, September 15, he was sentenced to seven years and four months in prison.
He will serve two-thirds of that sentence in prison then will be liable for automatic deportation, Judge Tony Hyams-Parish said.
Prosecutor Ravi Dogra said: “The defendant claims his date of birth is January 1, 1988, which would make him 37.
“He entered the UK as an asylum seeker from Sudan and we think that was in 2015. I’m afraid the Crown aren’t able to confirm if that date of birth is accurate.”
Alkhair left his wife and two children behind to flee persecution and had been granted permanent leave to remain the UK, defence counsel David Smith said.
He was working as a labourer on a building site prior to this offence but has been held in custody since his arrest.
Judge Hyams-Parish told Alkhair: “You took advantage of a woman who was clearly incapable of consenting to have sexual intercourse or indeed engage in any kind of sexual activity because she was so intoxicated and unconscious, it would seem from a combination of drinks and drugs.
“I cannot imagine what it must be like to know someone has violated you as you did to the complainant in this case and not remember anything about it.”
He added: “Had you not been disturbed, or even if you had been disturbed minutes later, you would have gone on to rape her.”
Alkhair will be liable to automatic deportation unless he wins an appeal.