It took four fights covering eight years, a lot of controversy and talking, but Marquez finally got vengeance for what he believed to be wrong decisions the first three times these two superstars locked horns.
The first fight, in 2004, was a nail-biter, though Pacquiao probably should have gotten the decision by virtue of scoring three knockdowns in the first round. Marquez did make a good comeback to get the fight to the judges, who scored the bout a draw.
The rematch came four years later, with Pacquiao winning a split decision in another ridiculously close fight that could realistically have gone either way.
The third fight, in 2011, is the one that set the Internet on fire. Marquez fans, as well as Pacquiao detractors, were incensed when the decision went to Pacquiao even though Marquez peppered him with counter-punch after counter-punch.
A victory in this fight has to be sweet redemption, not to mention validation, for Marquez after all these years of proclaiming himself to be a superior fighter.
For Pacquiao, you have to wonder what this loss does to his status. Everyone felt that he was robbed against Timothy Bradley earlier this year, but when you go back to his last fight with Marquez, this makes three straight fights where he has lost or looked really vulnerable.
There was a time when Pacquiao would breeze by anyone who got in his way. That time seems like a distant memory. He is still one of the best boxers in the world, but he is no longer head and shoulders above everyone else like he used to be.