LAS VEGAS (Ticker) -- Sugar was too sharp for Shannon.

"Sugar" Shane Mosley remained unbeaten as he hammered Shannon Taylor for five rounds Saturday night and retained his WBC welterweight title with a one-sided technical knockout.

From the opening bell, Mosley was too much for the previously unbeaten Taylor. He scored the bout's only knockdown with a thunderous right hand late in the first round and pounded the Australian's body thereafter.

"I wanted to break his body down to take away his power, and that's what I did," Mosley said.

In the final seconds of the fifth round, Mosley sandwiched a left hook to the body between hard rights to the head that had Taylor stumbling back to his stool following the bell.

After conferring with the ring physician, referee Vic Drakulich stopped the bout before the bell to begin the sixth round.

Having won every round on all three judges' scorecards, Mosley improved to 37-0 with 34 knockouts as he did nothing to diminish his standing as the best pound-for-pound fighter in the world.

Taylor came in with a mark of 28-0-1 and 20 knockouts, compiled mostly against fighters from his homeland. He had no answers for Mosley's speed or power, both of which drew oohs and aahs from the crowd at Caesars Palace.

"You can't call yourself the best if you don't fight the best," a dejected Taylor said afterward. "He's super sharp."

In the final seconds of the opening round, Mosley floored Taylor with a straight right hand that drew blood from the nose.

"He heard the tap on the board (indicating 10 seconds left in the round) and he thought the round was over," Mosley said. "It was a flash knockdown, but he was hurt."

"That's why Shane's the best," said Jeff Fenech, Taylor's trainer. "One punch can do it."

Taylor took a standing eight count before the bell rang, then spent the rest of the fight baring his body to protect his face. Mosley went to work on Taylor's ribs and stomach.

In the fourth, a frustrated Taylor bear-hugged Mosley and ran him back into a corner. Drakulich immediately deducted a point and the fighters touched gloves.

"He's a puncher. He can turn a fight with just one punch," said Mosley. "The ref did a good job of controlling the fight at the end."

This was Mosley's second title defense since dethroning Oscar de la Hoya in a 12-round decision last June. He was fighting for the first time since a sixth-round TKO of Antonio Diaz in November.

"He beat Oscar and other great fighters," Taylor said. "I just got beaten by the pound-for-pound best."

Having already moved up from lightweight, Mosley would not mind climbing again to junior middleweight to take on Felix Trinidad, the WBA and IBF champion, in what would be a lucrative bout.

If he cannot get a bout with Trinidad, Mosley said he would like to unify the welterweight division. Andrew Lewis holds the WBA title and the IBF crown is vacant.

On the undercard, Lance "Mount" Whitaker continued his march up the heavyweight rankings with an awesome second-round knockout of Russia's Oleg Maskaev.

The 6-8 Whitaker (23-1, 19 KOs) actually lost the first round as he measured his opponent. Less than a minute into the second round, he unleashed an overhand right that stunned Maskaev and followed with a flurry before crushing him to the canvas with another overhand right.

Maskaev was counted out by referee Jay Nady at the 1:03 mark and dropped to 20-4.