Tony Bellew humbled his bitter British rival David Haye with a shock 11th round win in a non-title heavyweight fight at the O2 in London on Saturday.
Former WBA world heavyweight champion Haye suffered a suspected snapped Achilles tendon in the sixth round, leaving him an easy target as he stumbled and limped around the ring for second half of the fight.
Unable to move away from Bellew's blows, Haye got up from a count in the seventh round and bravely battled on until he was knocked out of the ring in the 11th round.
As he was climbing back into the ring, Haye's trainer Shane McGuigan threw in the towel to the stop the fight.
Haye afterwards called for a rematch after a third career loss in his 31st fight which has shattered his hopes of facing one of the world heavyweight champions in the next 12 months.
Bellew, the reigning WBC world cruiserweight champion who stepped up a division, enjoyed silencing Haye's pre-fight taunts and claimed: "I'm the most valuable heavyweight in the world outside the world champions."
Bellew said he would be willing to meet Haye again at Goodison Park, home of Everton football club.
Among many insults which included the threat to "hospitalise" Bellew, Haye said he would quickly knock out his opponent in the non-title heavyweight bout.
Few predicted "Bomber" Bellew would pull off an upset and bookmakers made him 4-1 to win, with Haye a long odds-on betting favourite at 1/6 on.
Bellew, who stepped up a division to face Haye, a former world champion at cruiserweight and heavyweight, profited from Haye's injury but had shown promise in the early rounds.
Haye, who flew to Germany earlier in the week to see a specialist about his Achilles, bravely fought on through the pain but his hopes of another big pay day are now in serious doubt after a third career loss.
Four times Bellew was able to get to Haye and a left hook knocked the Londoner off balance.
Haye, 36, who was last world heavyweight champion in 2011, missed with a lot of punches in the opener but had more success in the second.
Bellew, 34, who weighed in nearly a stone lighter than 16-stone (101 kg) Haye, caught Haye with right hands in the third when his rival missed with shots.
After failing to stop it early, Haye continued to try to land the one big knockout punch and in the fourth he nearly did it with a right and left to the jaw that shook Bellew.
Bellew did well to back pedal away from trouble but was caught by another big right on the ropes in the fifth round.
But the fight turned in the sixth round when Haye slipped, perhaps on some water, and appeared to damage his right Achilles.
After twice falling to the canvas, which were ruled no knockdowns, Haye was left limping around the ring and an easy target for Bellew who forced a legitimate knockdown later in the round.
Haye refused to pull out at the end of the round but it was just target practice for Bellew in the seventh round with Haye unable to move away from danger.
Haye stumbled back to his corner at the end of the seventh like a drunk at times as Bellew landed clean shots at will. In the 11th, Haye was sent through the ropes by a combination and McGuigan had seen enough.