'Calculated killer!': Masvidal coach releases footage of flying knee drill before UFC 239 (VIDEO)

The stunning flying knee used by Jorge Masvidal to KO Ben Askren at UFC 239 on Saturday may have seemed like a moment of spontaneity but Masvidal had been working on that specific technique just 48 hours before the fight.

READ MORE: 'Ben’s still sleeping': Masvidal goads 'bum' Askren after record-breaking KO at UFC 239

Masvidal's coach at American Top Team, former WEC champ Mike Brown, released footage on Instagram which shows his fighter practicing the flying knee which would bring about a swift conclusion to his bout with heated rival Askren last weekend.

The footage shows the fighter drilling the move exactly as how he used it in the fight's opening moments, as he begins in somewhat of a disarmed fashion and moves to the right before exploding forward and aiming the jumping knee at a heavy bag held by Brown. 

"A part of me just wanted to throw it out there so he knew: If you do shoot like an idiot like you only know how too, your head is going to get clipped," Masvidal said to the media after the fight. "He took the bait. I put my hands behind my back, he probably through we were going to f***ing patty-cake it up, but he walked right into it."

Masvidal evaluation was a little less dramatic than his coaches, simply claiming he was "sharpening the sword" for his battle against Askren.

Instagram / Mike Brown

The official time of Masvidal's win was five seconds but replays have shown that the fight could easily have been called after two or three seconds had the referee been in a closer position to halt the action.

The finish, which was nonetheless the quickest ever in the history of the UFC, was as spectacular as it was stomach-turning, with Askren visibly affected by the strike for several minutes after the brief fight's conclusion.

Brown, the apparent architect of this move, will next turn his attention to another of his proteges as they attempt to get the best of an undefeated wrestler when Dustin Poirier takes on Khabib Nurmagomedov in September.