Georges St. Pierre and B.J. Penn both talked of legacy and the desire to be known as the best fighter in the world. But Penn pointed to a more basic motivation driving him ahead of Saturday's showdown at UFC 94.

“I just want to kick his ass,” the Hawaiian fighter said Wednesday at the pre-fight news conference.

Penn did just that in the first round the first time they met, at UFC 58 in March 2006. Penn used his striking skills to bust the Canadian open and by the end of the round, St. Pierre’s face was a mask of blood. He was so befuddled he even headed to Penn’s corner instead of his own when the round ended. St. Pierre bounced back, gamely using his wrestling skills to take Penn down and suppress him in the final two rounds. St. Pierre won a split decision, but it was hard to tell after the fight.

Almost three years later, they meet again — Saturday in Las Vegas.

St. Pierre (17-2) holds the welterweight title at 170 pounds while Penn (13-4-1), a former 170-pound champ, holds the 155-pound belt. The fight will be contested at 170 pounds, with St. Pierre’s title on the line.

Now the Montrealer wants to finish Penn — and leave him in his tracks.

“I want to be the best fighter in the world, known as the best pound-for-pound in the world,” St. Pierre said.

Both have to make 170 pounds at Friday’s weigh-in and Penn — at 171 pounds — is pretty much there already. His camp says he will probably be down to 175 or 176 pounds Thursday, squeezing out the final few pounds in the sauna.

“This is one of those fights that’s going to make history,” said St. Pierre. “I’m ready for it. I’ve never been so excited for a fight and I can’t wait.”