Manny Pacquiao, right, delivers the final knock-down punch to Ricky Hatton during the second round of their junior welterweight boxing match on Saturday in Las Vegas. ((Isaac Brekken/Associated Press))

Manny Pacquiao of the Philippines was dominating. Britain's Ricky Hatton was helpless.

Pacquiao cemented his claim to being the best pound-for-pound boxer Saturday night with a spectacular performance that ended with Hatton sprawled out on the canvas in Las Vegas after a devastating left hand to the head late in the second round.

Coming off an overwhelming win over Oscar De La Hoya, Pacquiao was even better against Hatton, knocking him down twice in the first round before finally stopping him with a vicious left hand that dropped Hatton for good in the 140-pound title bout.

Referee Kenny Bayless took one look at Hatton and declared the fight over at 2:59 of the round.

"I didn't have to count," Bayless said.

Pacquiao needed less than half a round to figure out the onrushing Hatton, hitting him with a flurry of punches midway through the first round before putting him down for the first time with a right hook to the head.

Flattened by left cross

Hatton got up at the count of eight, but Pacquiao landed another flurry and dropped him again just before the end of the round.

Hatton attempted to carry the fight to Pacquiao in the second round but was mostly ineffective as Pacquiao sized him up for a big punch. It finally came at the end of the round when he landed a left cross that flattened the English fighter.

"I'm surprised the fight was so easy," Pacquiao said. "He was wide open for the right hook. I knew he would be looking for my left."

Pacquiao was a 2-1 favourite, but few thought Hatton would go easily. His only loss came when he was stopped in the 10th round by Floyd Mayweather Jr., and he built a career and a reputation as a tough and aggressive fighter who wore his opponents down.

But he stood no chance against Pacquiao, whose punches came straight down the middle and landed with increasing frequency as the fight went on.

"I was just doing my job," said Pacquiao, who is a national hero in the Philippines and is fast becoming a hero among boxing fans. "I always try to do my best in the ring."

Pacquiao (49-3-2, 37 knockouts) earned $12 million US for the fight, while Hatton (45-2) was paid $8 million.