Death-Defying Stunt Off Ladder!!!

Wowwwwwww!!!!!!!!!!!

Pro wrestler Darby Allin tore down the house Wednesday night at AEW Dynamite when he pulled off a death-defying stunt ... jumping off the top of a ladder and crashing into 8 steel chairs -- and Jeff Hardy, too!!

It all went down at UBS Arena at Belmont Park in Long Island, NY, when Allin (with Sting) was in action against Jeff (with his brother Matt) in a first round, anything goes match in the Owen Hart Men's Foundation tourney.

Hardy and Allin were exchanging blows all match, but things picked up when the "KING of the extreme" set up a ladder in the middle of the ring ... with obvious plans on using it.

Allin, who introduced multiple chairs into the match that he pulled…