Two of the world’s premier pound-for-pound mixed martial artists stood on the stage together one last time, as the most-anticipated bout of 2009 got the green light.

Welterweight champion Georges St. Pierre checked in at a fit 170 pounds for his rematch with lightweight king B.J. Penn (168) in the UFC 94 “St. Pierre vs. Penn 2” main event on Saturday at the MGM Grand Garden Arena in Las Vegas. The 18 other fighters booked to compete also made weight without incident at Friday’s official weigh-in.

Scheduled to make his second title defense since he regained the undisputed welterweight crown in April, St. Pierre (17-2) will carry a four-fight winning streak into the bout. The 27-year-old French Canadian took a controversial split decision from Penn at UFC 58 three years ago, and the two of them have been on a collision course ever since. Arguably the sport’s top athlete, St. Pierre has all but wiped out the welterweight division, with victories against future hall of famer Matt Hughes (twice), Josh Koscheck, Matt Serra, Karo Parisyan and Jon Fitch. Should he survive his showdown with Penn, St. Pierre could conceivably move up to middleweight to challenge UFC middleweight titleholder Anderson Silva sometime in 2009.

“I’ve never been so excited for a fight,” St. Pierre said. “I never wanted to win a fight so bad. Tomorrow night, don’t blink.”

Penn (13-4-1), a one-man gang as a lightweight, has enjoyed mixed success at 170 pounds. The popular 30-year-old Hawaiian has not competed there since he succumbed to strikes against Hughes at UFC 63 in 2006. Three dominant performances at 155 followed, including a submission victory against Joe Stevenson that brought him the lightweight belt a year ago. Penn last appeared at UFC 84 in May when he picked apart top contender Sean Sherk en route to a third-round stoppage.

“I’m ready,” Penn said. “I’ve got nothing else to say. Let’s fight. Let’s go.”

Though the St. Pierre-Penn rematch has received a bulk of the attention, it is not the only bout of importance on the card.

Unbeaten light heavyweights Lyoto Machida (206) and Thiago Silva (206) will square off in a battle that likely will thrust the victor into title contention.

The polarizing Machida (13-0) holds victories against Stephan Bonnar and former middleweight champion Rich Franklin but has become something of an enigma since he made his UFC debut in 2007. The 30-year-old has rattled off five consecutive wins since, though four of them went the distance. Some have labeled him boring; others view him as the game’s finest tactician.

Now based at American Top Team, Silva (13-0) has bullied his way into the limelight with nine first-round finishes in 13 career fights. The 26-year-old Brazilian has stopped all four of his foes inside the Octagon, including Antonio Mendes, whom he struck into submission at UFC 84 eight months ago.

UFC 94 “St. Pierre vs. Penn 2”
Saturday, Jan. 31
MGM Grand Garden Arena
Las Vegas

UFC Welterweight Championship
Georges St. Pierre (170) vs. B.J. Penn (168)

Lyoto Machida (206) vs. Thiago Silva (206)
Karo Parisyan (170) vs. Dong Hyun Kim (171)
Nathan Diaz (156) vs. Clay Guida (156)
Stephan Bonnar (206) vs. Jon Jones (206)
Jon Fitch (171) vs. Akihiro Gono (171)
Manny Gamburyan (155) vs. Thiago Tavares (155)
Chris Wilson (170) vs. John Howard (171)
Jake O'Brien (205) vs. Christian Wellisch (206)
Matt Arroyo (171) vs. Dan Cramer (171)