Eliska Novotna, 23, was found guilty of the culpable homicide of Arunus Ramanauskas at the property they shared in Easter Happrew Farm, Peebles on Saturday, 8 October 2011.
Officers found the 39-year-old in his home with a number of puncture wounds to his chest.
Despite the efforts of ambulance staff, Mr Ramanauskas died at the scene.
Novotna had claimed she was acting in self defence after he tried to get her to perform a sex act.
Detective Chief Inspector Jim Robertson, who led the investigation, said: “The full circumstances as this incident in which Arunus Ramanauskas suffered ultimately fatal injuries may never be known.
“However, Lothian and Borders Police conducted a robust investigation to prove that Eliska Novotna was involved in his death and today’s verdict reflects that.
“My deepest sympathies remain with Mr Ramanauskas’s family at this time and I hope they can now begin to move on with their lives.”