Manchester's Ricky Hatton beat Mexico's Jose Luis Castillo with a stunning fourth-round knockout in Las Vegas.
Hatton is flanked by Wayne Rooney and Marco Antonio Barrera
Hatton, 28, started furiously, swarming all over Castillo and landing the better shots in the first three rounds.
Castillo, 33, was docked a point at the start of the fourth before Hatton landed with a savage left to the body that sent his rival down for the count.
The impressive nature of Hatton's victory could pave the way for a super-fight with Floyd Mayweather.
Mayweather has twice struggled to outpoint Castillo but it was a different story for a pumped up Hatton at the Thomas and Mack Center.
Cheered on by an estimated 10,000 British fans, Hatton, billed for the bout as the Manchester Mexican, entered the ring in a sombrero and poncho in Manchester City colours.
Manchester United's Wayne Rooney and Mexican legend Marco Antonio Barrera had the honour of carrying his championship belts.
There was more action in those four rounds than in Floyd Mayweather's last half dozen fights
Hatton was fastest out of the blocks and Castillo briefly touched down in the opening stages, although referee Joe Cortez ruled it a slip.
The English fighter rammed home two crisp uppercuts as both men bored into each other in the centre of the ring, although it was an untidy start to the fight.
Hatton kept up the pressure in round two, landing with a couple of useful lefts to the body and continuing to outmanoeuvre Castillo on the inside.
Castillo came into the fight in the third, letting fly with two hurtful left hooks to the body that had Hatton wincing.
But the Mexican was deducted a point for repeated low blows at the start of the fourth, and when the action resumed, Hatton poleaxed Castillo with a brutal left hook to the kidney.
Castillo twisted, crumpled to one knee, gumshield hanging from his mouth, and Cortez counted him out after two minutes and 16 seconds of the round.
Hatton delivers the decisive blow to Castillo in Las Vegas
It was the first time in Castillo's 17-year professional career that he had been sent to the canvas.
Hatton, who is now undefeated in 43 professional fights, said: "I trained for 12 rounds of pain tonight. I told everybody that I've never had a training camp like it before and I think it showed.
"Sometimes I have tried too hard to put on a show and that has got me in trouble in the past.
"I think I've definitely proved the fat man is back. I hit him with a left and then another left and it just about cut him in half.
"I was going for the body from the first round and I've got him with one of the best shots I've ever thrown.
He got me good - it was a perfect shot
"It was a big shot in the first round and I know he winced. I went for the body time and again after that although I should have shown a bit more caution.
"The greatest night of my life was in Manchester against Kostya Tszyu but beating by KO one of the pound-for-pound best and coming halfway across the world to do it underlines what I'm all about.
"There was more action in those four rounds than you'd have had in Floyd Mayweather's last half dozen fights."
Castillo, who fell to 55 wins and eight defeats, admitted he had been the victim of a "perfect shot".
"He got me good," said Castillo. "It was a perfect shot. I couldn't breathe. I couldn't get up."
Next for Hatton could be a match-up with New York's Paul Malignaggi, who holds the IBF title.
The 26-year-old won his belt against Australia's Lovemore N'dou last Saturday and his only defeat was against Puerto Rico's Miguel Angel Cotto in 2006.
Also in the mix is former three-weight world champion Shane Mosley, who outclassed Luis Collazo, a former victim of Hatton, in his last fight in February.
On the undercard, Hatton's brother Matthew won a unanimous decision over Puerto Rico's Edwin Vazquez.
After the fight, the younger Hatton said he would like to challenge Scotland's Kevin Anderson for the British welterweight crown.