Floyd Mayweather Jr. insisted all week that he is the world's best pound-for-pound boxer. After his performance Saturday night at Boardwalk Hall, Washington's DeMarcus Corley is one person who won't argue with him.

Mayweather, making his debut at 140 pounds after winning titles at 130 and 135, out-boxed and out-punched Corley, knocking him down twice and winning a rout of a unanimous decision, 119-107, 119-108, 118-108, in front of a crowd of 6,103.

Corley "was tough, he had good, solid punches," Mayweather said. "But I was never in any kind of danger, and I was never in trouble during the fight."

The fight was billed as a WBC elimination bout, with the winner earning a shot at 140-pound champ Arturo Gatti. Mayweather's domination of Corley, however, will put the rest of the division on alert.

"I respected his hand speed, not necessarily his punching power," Corley said. Much was made of the five-pound leap Mayweather (32-0) would be making for the fight, and the left-handed Corley promised to put pressure on Mayweather throughout the bout. But Mayweather seemed unafraid to mix it up with Corley (28-3-1) and often dictated the pace of the fight.

Mayweather landed several good shots in the first round, culminating with a right hook just below Corley's throat that sent Corley momentarily staggering backward.

The tempo picked up in the fourth round. Corley landed a big right at the start of the round that moved Mayweather back to the ropes. From there Corley trapped him, scoring with lefts and rights to the body and up high. Just when Corley seemed in command, however, Mayweather escaped and hurt Corley before the boxers traded blows in the middle of the ring.

"When I hurt him with those looping punches in the fourth round, I should have gone after him," Corley said.

The fight slowed down a bit in the sixth and seventh rounds as Mayweather boxed more conservatively. He stayed away more than he had in previous rounds, countering and slicing in right hands periodically. None of the shots did much damage -- as Corley pointed out by shaking his head sarcastically at one point -- but Mayweather clearly had the best of the action.

In the eighth, Mayweather caught Corley with consecutive uppercuts -- first to the body and then to the head -- to stagger Corley and force him to the ropes. As Mayweather moved in to trap Corley in a corner, Corley fled across the ring towards the opposite corner. Mayweather caught up to him on the way, however, and dropped him with a flurry of punches.

From there, Mayweather dominated. He hurt Corley with consecutive uppercuts in the ninth and in the 10th put Corley to the canvas again with a four-punch combination.

Mayweather showed speed, strength and courage -- willing to mix it up with a true 140-pounder. And his performance impressed even Corley's trainer, Don Turner.

"Mayweather can flat-out fight," Turner said. "He's like magic. He makes you move into the punches."

While the fight further legitimized Mayweather's reputation as one of the game's best, it left Corley in limbo. Saturday night's decision was Corley's second consecutive damaging defeat. Last July, he lost his title in a split decision to Zab Judah.

Corley, 29, may have lost much of his marketability in a competitive division that boasts Judah, Gatti, Washington's Sharmba Mitchell, Kostya Tszyu and Britain's Ricky Hatton, to name a few with considerably greater drawing power.

Even when Corley held a belt, it was the lightly regarded WBO's, and he had neither the marquee victories, nor the style and charisma to excite fight fans. After his loss to Judah -- his first truly big-name opponent -- Corley knew he needed a win Saturday night to keep his name in the conversation of 140-pound competitors. The WBC called this fight an elimination bout, and that is exactly what it might do to Corley.

Mayweather, meantime, added another line to his impressive resume and put himself in position for a shot at Gatti and a belt in a third weight class.