Greg Hardy made one hell of an impression on Dana White — knocking out his opponent 57 seconds into his UFC Contender Series fight.

Hardy was matched up against another former NFL lineman Austen Lane Tuesday night — and the winner gets an opportunity to earn a UFC contract … if White feels like the fighter has earned it.

Hardy — who was undefeated in his previous 3 amateur MMA fights — hit the Octagon like a violent tornado … and rocked Lane — who was 2-0 with 2 KOs in his previous pro fights — with a couple of devastating haymakers.

Lane went down … and the ref called it immediately for Hardy.

Hardy was exiled from the NFL in 2015 because of off-the-field legal issues involving domestic violence and drug possession.

Hardy was convicted of domestic violence in 2014, but the charges were later expunged from his record after the victim failed to appear in court for a jury trial during his appeal. Hardy has denied ever hitting a woman, but four dozen photographs of the woman that were evidence in the trial and later published online by Deadspin show bruises to her chin, neck, arms, back, legs and feet.

In an interview Friday, Hardy referred to White as “an angel” for giving him an opportunity. White has stated Hardy has turned his life around and deserves a second chance.

Hardy is a former All-Pro defensive lineman who played for the Carolina Panthers and Dallas Cowboys.

Lane suffered the first loss of his pro career. He was drafted by the Jacksonville Jaguars in 2010, and left the league in 2014.