LAS VEGAS Manny Pacquiao will smile his way to the ring tonight. His opponent, Juan Manuel Marquez, will glare.
Pacquiao will try to beat his Mexican rival for the third time in four fights by again throwing caution to the wind with flurries of punches.
Marquez will again be more calculating. He has strengthened his body as never before at age 39, hell-bent to finally have his hand raised in victory against Pacquiao after suffering two agonizingly close decision losses and a draw.
"This fight is more important than the last three," Marquez said of tonight's non-title welterweight bout in Las Vegas. "Because it's for my legacy. The honor. The pride.
"For everything," he said.
In this rivalry, those words are as fiercely serious as the hard stare Marquez delivers.
Remember, in 2004, Marquez was knocked down by Pacquiao three times in the first round, scraped himself up each time and rallied to win nearly every other round to gain a draw.
Their 2008 battle was incredibly narrow, Pacquiao winning a split decision because of an early knockdown.
And their 2011 classic was met by a roar of boos when Pacquiao was declared the winner by majority decision.
Marquez, who weighed in Friday at 143 pounds, insisted this week that his career will not be defined by the Pacquiao fights.
Who's he kidding? Sports history is loaded with greats best remembered for losing to their foil, or falling short of clutching the brass ring.
Joe Frazier lost two of his three fights with Muhammad Ali. The Lakers' Jerry West was a tragic hero when his team lost six NBA Finals to the Boston Celtics' dynasty in the 1960s. Charles Barkley, Dan Marino and Barry Bonds are others who come to mind.
Is the die cast for Marquez? Or can he alter the story?
Pacquiao's trainer, Freddie Roach, doesn't expect Marquez to change, not after 61 pro fights: "He's a counterpuncher through and through. I wish he'd be more aggressive like he's saying. I don't think it'll happen," Roach said.
Pacquiao, who weighed in at the class limit of 147 pounds, said a major reason he wanted a fourth Marquez fight is to settle how each fighter will be remembered.
"It's not about the size. It's about the speed," Pacquiao said.
Right now, that's the epitaph. Marquez has one last chance to pound in new words.