Manny Pacquiao may be the greatest fighter in the world today, but that's a distinction that doesn't come without some trials and tribulations.
One of the things that is most engaging about the Marquez fight is the fact that Pacquiao has struggled against La Dinamita in the past, and it might seem like Marquez has finally learned enough about Pacquiao to push him past the tipping point.
But, were those Pacquiao's toughest bouts? He has, after all, lost three times, and none of those came against Marquez.
A look at the toughest battles of Pacquiao's illustrious career.