Ricky Hatton's pound-for-pound dream has been wrecked inside two shocking rounds.
Manny Pacquiao put the Hitman down twice in the first before ending a one-sided contest with a chilling left hook one second from the end of the second.
It was such a bad knockout that Hatton was out before he hit the canvas and he needed treatment before finally 0 thankfully - getting to his feet.
Whether he climbs back into a boxing ring again, is doubtful.
Hatton did no interviews, had to be helped from the ring and was surely headed for hospital. And possible retirement.
When his head clears he will realise that the performance was a complete and utter disaster. He came to Vegas dreaming of being crowned the best boxer on the planet. He will leave after an absolute nightmare.
At least it was a short one. Freddie Roach's initial three-round prediction was not far off the mark in the end. Pacquiao's trainer also said it was too late for the Hitman to change his style - and that was just as accurate.
Ferocious
In six ferocious minutes of action, there was no sign of any boxing skills, no head movement, no cunning whatsover as he tried to close the gap and take Pacquiao on on the inside.
Instead it was the Hatton of old. Walking straight forward, square on and, as he did even on that fateful night when he forced Kostya Tszyu to quit, taking way too many shots.
Reports of a rift with trainer Floyd Mayweather Snr on the eve of the biggest fight of his life can't have helped. If there had been problems - and in five minutes 59 seconds Hatton did little to dispel the rumours - they were cruelly exposed by the Filipino phenomenon, who now stands alone at the top of boxing's tree.
Hatton's plan to chop him down had been based on getting in close and in the very first clinch of the fight, he did get two sneaky shots in on the inside. But Pac Man hadn't even begun to fight.
A few seconds later and he was in the swing, catching his man with a right and even when he was pinned on the ropes, he slipped out untroubled.
Knowing his speed would keep him clear of any one-dimensional danger, he was then able to stand his ground in the face of thoughtless attacks and let his own fists fly.
Stunned
A left-right-left combination soon had Hatton cowering, then a huge right hook, signalled the beginning of the end.
Down Hatton went, stunned, but got back to his feet at eight. It was no flash knockdown, no lucky counter, no fluke. It was speed, timing, power; everything a boxer craves, everthing Hatton had promised - and it was to be repeated.
The next time he stuttered forward, a straight left repeated the punishment and had the Hitman on his back again with 55 seconds of the first round still remaining.
Juan Manuel Marquez might have survived three first-round knockdowns against Pacquiao five years ago, but even though Hatton got up again and held on for the ball, this was so patently different. Pacquiao had, as promised brought plenty power up to 140lbs to match his pace.
Hatton did at least catch his man at the start of the second, but still he was hunting in straight lines, not using, never mind moving his head. Soon enough another left landed and sent his head rocking back, while Pac Man let loose three or four-punch combinations and stepped out of range as Hatton lunged forward.
It was all too familiar and although he managed to mess Pac Man up for the next chunk, Bayless warned him for a low blow and roughing on the inside as desperation took over far sooner than anyone had dared fear.
Horrendously
How he made it to within a whisker of the end of the session perhaps only Pacquiao can answer, but just as the seconds were getting ready, the Hatton dream was ruined. Absolutely, unequivocally and, as fiancee Jennifer's piercing ringside scream will testify, horrendously.
This time he didn't even walk onto the shot. Almost casually, Pac Man prodded out half a jab before unleashing a lightning fast left hook flush to the chin. Hatton toppled to his left, smacked the canvas hard and did not even need a count.
He did need extensive treatment and he will now need a serious assessment of just where to go next.
Pacquiao, in contrast, can look forward to the winner of Floyd Mayweather Jnr and Marquez later this year.
On this chlling evidence, he can do so with supreme confidence. Boxing has a new pound-for-pound king. And sadly, he was a class above the same old Ricky Hatton.