Sorin Mischia knew a relative of the victim and had gone to their shared home in Erdington after drinking and taking drugs.
The 31-year-old knocked on the door of the victim's room armed with a kitchen knife and attacked her on October 18 last year.
Officers arrested him after the attack, in the early hours of the morning.
Mischia had claimed to have been acting in-self defence.
But this was dismissed by a jury and he was convicted of wounding.
Mischia, of Church Lane in Erdington, was locked up for 12 years in prison at Birmingham Crown Court on Tuesday.
Detective Inspector Gemma Currie, from West Midlands Police's CID, said: "This attack caused lasting physical and mental injuries, and I’d like to pay tribute to the courage of the victim whose testimony in court was vital in securing the offender’s conviction.
"Mischia will quite rightly spend substantial time behind bars."