David Haye's career was left in ruins after he again lost to Tony Bellew, this time following a fifth-round stoppage in their rematch at London's O2 Arena.
Heavyweight Haye had conceded he would have no choice but to retire if he suffered another unexpected defeat.
At 37 years old and having proved increasingly injury prone, Haye's reputation has been left beyond repair after successive defeats by an opponent who was a light-heavyweight, while he reigned as the WBA heavyweight champion at his peak.
Regardless of his claims he would rediscover the reflexes and power that had brought him such success, one of Britain's finest fighters looked older than ever when being dropped three times and to the extent he would be foolish to fight on.
An Achilles injury when losing in the 11th round last March had then robbed Haye of his power and balance, but it had also masked the ring rust that had built after previously fighting less than three rounds since 2012.
To overcome an opponent enjoying the finest run of his career, and in his first fight since appointing Ismael Salas as his new trainer, he needed to swiftly begin to time Bellew before the likelihood of him tiring after the opening rounds.
He had come to the ring considerably lighter than 14 months ago, but Bellew regardless remained an awkward style of opponent who demanded he become the aggressor instead of fight on the back foot, where he was once consistently at his best.
Bellew, 35, was also lighter having recognised he is not a true heavyweight, and while struggling until landing the fight-changing right hand that put Haye down in the third, he then exposed his rival as shot.
Despite improving on his worst performance and beginning convincingly - and to the extent Bellew was under constant threat - following an exchange in the third Haye proved no longer able to take a punch.
The younger fighter launched forward recklessly to force his decorated opponent back against the ropes, and landed the explosive right hand that put him down for the first time.
When he returned to his feet Haye remained unsteady and struggled to defend himself, again going down following another right hand.
Only the round's end rescued him from an earlier defeat, and after he spent the fourth attempting to recover - appearing increasingly tired in the process - his desperation to land the punch that could have rescued him in the fifth again left him exposed.
While both swung, Bellew this time landed a powerful left hook, again sending Haye to the canvas and leaving him unsteady to the extent that when he returned to his feet and was unable to defend himself, referee Howard Foster intervened to save him from further punishment after two minutes and 14 seconds.
Haye, who until the first knockdown had been winning and landing regularly, had intended to use victory over Bellew to secure a lucrative fight with IBF, WBA and WBO heavyweight champion Anthony Joshua.
That he then folded so quickly demonstrated the extent of his decline, and while Bellew is also expected to retire having achieved all his ambitions, it is the loss of Haye - considered one of the best cruiserweights in history - that will create the greater void.