Tony Bellew dramatically secured one of the biggest upset victories in British boxing history when David Haye was withdrawn in the 11th round at London's O2 Arena after suffering a suspected Achilles injury.
The grudge match that had been considered a mismatch became a nightmare for Haye from the sixth, when after losing his balance the injury occurred and left him barely unable to stay on his feet.
He bravely persisted from then until the 11th, struggling as much for balance as against Bellew and clearly on the verge of exhaustion. He was finally pulled out by his trainer Shane McGuigan when he was knocked through the ropes and almost out of the ring amid his pursuit of one conclusive punch.
The 36-year-old's midweek trip to Munich had been followed by reports of an Achilles injury and his subsequent claims he had started them as a mind game.
Instead of him proving both too big and too skilled an opponent for Bellew in his opponent's first fight in the heavyweight division, his fitness and technique unravelled to leave him staring at the end of his career.
Bellew's greatest chance of success came in spoiling throughout the opening rounds in an attempt to survive and to see if Haye would tire and become vulnerable thereafter.
The older fighter had fought less than three rounds in almost five years and his heavier 16st 9oz frame - one he insisted was necessary to avoid injuries recurring - would likely have reduced his already questionable stamina.
Haye was again far slower than he was at his impressive peak, but despite questions surrounding his ability and fitness in the build-up to this fight, his power was also unexpectedly lacking.
The once-great fighter reliant on his explosive power and reflexes frequently showed signs of rust and technical decline amid Bellew's early success in landing both left and right hands.
For all of his bravado, Haye became tentative, reluctant to throw because of Bellew's superior speed until entirely confident his punches would land.
Speaking to Sky Sports after the fight, Bellew thanked Haye for the opportunity.
"David, I thank you from the bottom of my heart, because he could have picked a lot of different guys.
"It was genuine people. I have got so much respect for David as a fighter. We can do it again."
Haye added: "I did not expect him to have the chin and the durability that he has. Bellew, by far, was the better fighter tonight...I believe I’m more gifted but he had a bigger heart tonight. He took my best shots, got back up, and put me down.
"I’ve never been in a fight like that before. He’s the man.
"I'm at his mercy - I can't think of world titles now."