UPDATE: To watch Manny Pacquaio vs. Juan Manuel Marquez 4 full fight video highlights, including the epic knockout punch from this past Saturday night (Dec. 8, 2012), CLICK HERE.

It started with controversy, as most longstanding rivalries seem to do.

When Manny Pacquiao met Juan Manuel Marquez for the first time all the way back on May 8, 2004, the two fought for 12 bloody rounds. "Pacman" opened strong, knocking down his future arch enemy three times in the first round alone, before "Dinamita" made a roaring comeback.

The bout was ultimately ruled a draw, though that was only the case thanks to an error made on one of the judges scorecards.

The rematch took place nearly a full four years later on March 15, 2008. This time, Pacquiao was awarded the split decision victory, though it was yet another closely contested bout that had the Marquez camp calling for a trilogy. After initially refusing as much, the Filipino relented and the two battled again on Nov. 12, 2011.

And, again, it was almost too close to call.

The judges awarded the fight to Pacquiao, who admittedly had the better stats, though many felt Marquez was the rightful winner. The loud boos heard throughout the MGM Grand Garden Arena were a testament to that.

Now, just over one year later, the two will hook 'em up one last time, right back at the scene of the first three crimes in "Sin City." They're both a bit older, a bit more battle worn, and eager to finish this rivalry.

Who will emerge victorious, Maniacs?

Remember, our preliminary card quick results will begin to flow around 7 p.m. ET later this evening and run right on through to our main card PPV coverage, which is set to start at 9 p.m. ET, from the MGM Grand Garden Arena in Las Vegas, Nevada. Expect Pacquiao and Marquez to enter the squared circle for the fourth -- and likely final -- time around midnight.

To get up to speed on all the news and notes for Pacquiao vs Marquez 4 be sure to hit up our comprehensive event archive right here.