Martel Stirling’s victim told police that the 30-year-old had started a physical fight with her at a Birmingham club on March 6.
Ten days later, on March 16, she was at the Jam Roc Sports Lounge in Hackett Street, Hockley, when she saw Stirling again, with whom she had previously had a year-long relationship.
At around 2.25am as she stood outside the club, Stirling called out to her before pulling a black-handled flick knife from the waistband – and, lifting it above her head, brought it down striking the left side of her head and face.
The victim needed surgery and stitches to the wound which caused nerve damage and left her with a visible scar across her forehead.
Stirling initially told West Midlands Police that although he owned such a knife, he believed it was in storage.
But when officers arrested him at his new partner’s home they found a black-handled flick knife.
Stirling, of no fixed abode, was convicted of wounding causing grievous bodily harm at Birmingham Crown Court and sentenced earlier this month to 14 years in prison.
PC Andy Carnall from West Midlands Police's Public Protection Unit, said: "This was a terrifying attack for Stirling’s victim, who has been left permanently scarred and for all those who witnessed it that night.
“We take knife crime incredibly seriously and hope this lengthy sentence will act as a deterrent to anyone considering carrying or using any sort of blade."