Favourite Manny Pacquiao of the Philippines claimed the IBO light-welterweight title with a stunning second round knockout of British holder Ricky Hatton on Saturday.
The 30-year-old southpaw twice knocked the Englishman to the canvas in the opening round before ending the fight with a stinging left hook at the MGM Grand Hotel's Garden Arena.
The ring announcer said the bout, scheduled for 12 rounds, had ended two minutes 39 seconds into the round but that was later corrected by officials to two minutes 59 seconds.
"I was surprised that this was so easy but I've worked hard in training camp since the beginning of March," a beaming Pacquiao said in a ringside interview. "He was wide open for the right hook. I knew he would be looking for my left. It's nothing personal. I was just doing my job."
"This is as big for me as the De La Hoya win," the Filipino added, referring to his eight-round stoppage of 10-times world champion Oscar De La Hoya in Las Vegas in December.
Hatton, who had stopped American Paulo Malignaggi in November to retain his IBO light-welterweight belt, was left motionless in the centre of the ring for several minutes before being helped to his feet to sit on a stool.
"It was a hard loss but I am okay," the 30-year-old Manchester boxer said before being taken to the nearby Valley Hospital as a precaution. "I really didn't see the punch coming but it was a great shot. I know I will be okay."
Widely regarded as the best pound-for-pound fighter in the world, Pacquiao improved his career record to 49-3-2 with 37 knockouts. Hatton, who had never previously lost at his natural weight of 140 pounds, slipped to 45-2 with 32 knockouts.
Watched by a capacity crowd of around 16,000 that included Hollywood actors Christian Bale and Jack Nicholson and boxer Floyd Mayweather Jr, Hatton began the opening round by cramping Pacquiao and repeatedly forcing him to back-peddle.
However, the Filipino responded with a flurry of combinations late in the round, bloodying the Englishman's nose with a right hook before sending Hatton sprawling to the canvas.
Under concerted pressure, Hatton was pinned to the ropes before again being knocked to the floor by a Pacquiao left hook.
Pacquiao maintained the dazzling pace in the second round, landing a series of sharp punches and jabs before feinting with the right and unleashing a stinging left hook to the jaw, which put Hatton flat on his back.
"This was no surprise," said Pacquiao's trainer Freddie Roach, who had predicted his man would need only three rounds to win.
"Hatton pumps his hands before he throws a punch. He is a sucker for the right hook and this is what we worked on. He cocks back before he throws his punches. He fights the same way over and over. I studied tapes of all his fights for the last two months and I know him as well as I know my own fighter."
Pacquiao dominated the official ringside statistics, connecting with 73 of 127 punches thrown to 18 of 78 for Hatton. He also landed 65 power punches compared to Hatton's 16. Hatton's trainer Floyd Mayweather Sr said: "I really felt Ricky would get him. I don't want to go into it more than that."
Pacquiao could next fight the winner of the bout between Mayweather Jr, who announced earlier he would come out of retirement, and Mexico's Juan Manuel Marquez who meet in a non-title welterweight fight in Las Vegas on July 18.