Joe Calzaghe defied injury to produce one of the greatest performances of all time by a British boxer and unify the world super-middleweight titles in Manchester.
Calzaghe crushed Jeff Lacy, America's IBF champion and supposed next big thing, flooring him for the first time and claiming every round on all three judges' scorecards.
Calzaghe's mesmerising display was put into context by Lacy's venerable trainer Dan Birmingham, who said: "I have never seen a better performance by any fighter, anywhere in the world."
And it was all the more remarkable, given a serious left wrist problem which Calzaghe revealed had almost forced him to pull out of the fight three weeks ago.
Calzaghe said: "It was 50-50 and I seriously considered pulling out. I spoke to [promoter] Frank Warren who said 'if you pull out now, you'll never fight Lacy and the Americans won't be interested'.
"I had five days off and knocked my main sparring on the head. My dad sat me down and persuaded me to listen and said 'you're going to destroy this guy'."
Calzaghe, whose desire had been questioned when he pulled out of the original November date after breaking his hand in a routine defence against Evans Ashira, clutched an ice pack again yesterday morning.
But the pain proved well worth it as the 33-year-old Welshman laid claim to dominance of the 12-stone division, nine years and 18 defences after beating Chris Eubank to become WBO champion.
Lacy, also unbeaten, five years younger and rated by many good judges as the coming force of the sport, had been widely tipped to steal Calzaghe's crown. Instead he was left bloodied, battered and floored for the first time in his career in the final round as Calzaghe's whirlwind assault raged from the first minute to the very last.
The final scorecards of 119-107 (twice) and 119-105 were hardly required to establish Calzaghe's dominance. Only a late points deduction prevented him from a complete shut-out. Lacy, who required stitches around both eyes and also appeared to have broken his nose, said: "He came out and fought a remarkable fight. He fought a perfect fight tonight."
A spell-binding performance threatened to eclipse the greatest of British fight nights. Calzaghe - now unbeaten in 41 fights - announced himself as a true superstar.
A cracking right-hand counter -punch early in the first round set the tone with Lacy, already seeping blood from his nose, looking bemused and one-dimensional. The come-forward Floridian simply had no answer to Calzaghe's devastating hand-speed and the beautifully-paced assault continued in front of an exhilarated MEN Arena crowd of more than 16,000.
Lacy's left eye was so badly bloodied after the fourth that it required the attention of the ringside doctor, while his desperation to get back into the bout played right into Calzaghe's hands. Lacy may be nicknamed 'Left Hook' for his supposedly fearful shot which had helped lay out 17 of his victims but, even when he landed his trademark blow, Calzaghe contemptuously flapped it away.
Calzaghe said: "I have never been so focused and dedicated, not just physically but emotionally, because I realised how big this fight was for me.
"I've had eight years as champion and I got the chance to fight a guy like Lacy who was so highly-touted in America. I had been written off by so many people.
"This fight had been on my mind morning, noon and night. I am just over the moon and ecstatic. I demoralised him and I totally outclassed him."
Lacy's champion heart swept him forward for more punishment which worsened towards the end of the seventh when a crashing left had him out on his feet.
Referee Raul Caiz watched closely but deemed Lacy able to continue. Calzaghe did not relent, even with a points victory in the bag. Bizarrely docked a point in the penultimate round for pulling Lacy's arm behind his back, he simply stepped up the pace and came close to a final-round stoppage.
A smashing right hand dumped Lacy to the canvas for the first time in the American's career and the assault continued up to the final bell, which a shattered Lacy greeted with a knowing nod.
Warren said afterwards: "It is the best performance I have ever been involved with - he absolutely took the guy to school. Joe has gained the respect of the American market and he is going to go down in history as one of Britain's best."
* Enzo Maccarinelli has vowed to take on all comers, rather than wait around for his postponed WBO cruiser-weight title shot at the injured Johnny Nelson.
Maccarinelli was due to face Sheffield's Nelson, but the Sheffield veteran pulled out with knee ligament damage. British and Commonwealth champion Mark Hobson stepped in to take on the Welshman who holds the WBU belt and the pair produced an excellent bout as Maccarinelli won on points.
"I knew this was going to be a much better fight for the fans," said Maccarinelli. "All credit to Mark - he got me with some decent shots."