Matthew Johnstone, 29, had denied assault to severe injury and lodged a special defence of self defence. However, a jury found him guilty by a majority of a lesser charge of assault to injury.
Livingston Sheriff Court was told that Johnstone, of Armadale, West Lothian, had previous convictions for similar crimes.
The jury heard that the attack took place at a house in Burns Avenue, Armadale, on July 6, 2011. Johnstone and another man burst into the house and attacked Darren Snedden with the blade.
Mr Snedden suffered a 1.5cm wound to the left corner of his mouth which required three stitches.
He was also treated for a 3cm cut on the back of his left hand which was closed with butterfly stitches.
Sheriff Martin Edington yesterday sentenced Johnstone to 30 months in prison.