Their two previous bouts were so close that you could give the rounds to either one of them. Mr. Ron Nathaniel stated that Pacquiao knocked out Marquez thrice in their first bout, once in their second bout, & finally, no knock down was seen in their third encounter.
As if saying that Marquez progressed as a fighter by avoiding knockouts from Manny. Pacquiao has progressed as a tactical fighter through the course of their bouts. They fought in a chess matched game, but Marquez fell short towards the nearing rounds.
We might think that Manny's aggressiveness has declined against Manuel, but as Freddie Roach said, Marquez clearly as Manny's Number. Marquez was obsessed with Pacquiao, went even far by going to Manny's home country to challenge him personally. A reporter who personally talked to Juan Manuel once said, that he immersed himself on studying Manny very well and knows how to effectively neutralize him.
So if there is one boxer, who passionately followed, analyzed, & decoded the fights of Manny seriously, it is Marquez.. And you can imagine how frustrated he was, when finally given a chance, and still fell short of his mission.
Manny Pacquiao is clearly an aggressive complete tactical fighter, he missed giving Manuel a taste of knock out compared to their previous bouts, but he out-boxed Manuel in a way we're not used to seeing him lately in a close fight. If given a chance they meet again, in my heart I do believe Manny can knock him out this time.
It was just not Manny's night for an all out war of impressive fight, but a night of plain sweet science of tactical fight.