By Jake Donovan

Knockouts are memorable for all sorts of reasons. The punch that landed, the reaction of the knocked out fighter, the impact of a fight, avenging a prior loss, ending a well-publicized rivalry – all have played factors in past Knockout of the Year entries.

It’s not often that a knockout is memorable for all of those reasons. That’s what makes Juan Manuel Marquez’ 6th round blitzing of Manny Pacquiao in their December 8th fight in Las Vegas so very special.

Prior to the fight, there existed a fear that the rivalry had run its course. While there was no closure in 36 previous rounds of action, demand was scarce for a fourth fight. There was no title at stake for the fight, and it was also the first time that either fighter was coming off of a loss in facing the other.

Perhaps all of that helped to deliver the fight to which fans around the world were treated. Marquez, at 39 years old, was determined to gain long-sought revenge before heading down the home stretch of a Hall of Fame career. Pacquiao was anxious to restore recognition as the best fighter in the world, in spite of the controversial split decision loss against Tim Bradley six months prior.

With that came a restart to their longtime rivalry. Caution was thrown to the wind from the opening bell, as every punch was thrown with knockout intentions.

Pacquiao was never dropped in 38 previous rounds of action against Marquez, who was knocked down a total of four times in that stretch. The last came in the fourth round of their March ’08 rematch, with neither fighter floored nor coming close to it in their November ’11 entry.

That dynamic drastically changed when Marquez – already trailing through two rounds - put Pacquiao on the canvas in the third round. Suddenly, a series mired in scoring controversies finally carried a hint that an indisputable outcome was on its way – someone was getting knocked out.

You couldn’t blame Marquez for exuding confidence, but at the same time he should have also known better to have assumed victory at any point. The following two rounds saw Pacquiao punch his way back into the fight, including a fifth round that left Marquez stunned to the point of touching his glove to the canvas.

The sequence was a reminder that no matter how hard he tried, Marquez was never meant to win a decision in this series. Pacquiao reclaimed the lead on all three scorecards, as well as momentum after a strong finish to a fifth round honored by Boxingscene.com as 2012 Round of the Year.

Two minutes and fifty-nine seconds later, two more honors would be cemented. The fight as a whole took top honors in the year-end awards.

The last time Marquez was in a bout honored as Fight of the Year, his hand was raised in victory as a knockout winner. That moment came when he dropped and stopped Juan Diaz in the early moments of the ninth round of their first fight in Feb. ’09.

History would eventually repeat itself, though Marquez had to walk through hell to get there. Battered and bloodied for much of the round, there was growing concern if he would end the night on his back or even saved by the referee at some point later in the fight.

A single right hand removed any chance of that happening. Pacquiao walked right into the shot just before the bell, before collapsing face-first to the canvas. It was an “Oh sh*t!” moment reminiscent of Sergio Martinez’ one-punch 2nd round knockout of Paul Williams in their Nov. ’10 rematch.

With that single right hand late in the 42nd round of their 8 ½ year rivalry, Marquez finally found a way to secure a long-coveted victory the judges had denied him in three previous tries.

Among the many other honors earned in 2012, he also secured 2012’s Knockout of the Year.

HONORABLE MENTION (IN CHRONOLOGICAL ORDER)

Lucas Priori KO3 Roberto Correa (01/13/2012) –A matchup of pro debutants turned savage early on, with both fighters hitting the deck. The difference? Priori got up; Correa went down and out. A two-way exchange in the opening moments of the third round ended with a violent counter left hook that froze Correa before twisting and collapsing face first to the canvas.

Adonis Stevenson KO1 Jesus Gonzalez (02/18/2012) – Stevenson’s long road to a future title shot against Carlo Froch gained traction in this semi-final eliminator. A straight left hand from the hulking super middleweight landed flush on Gonzalez’ temple, putting the fringe contender down and out midway through the opening round.

Mikkel Kessler KO4 Allan Green (05/19/2012) – The fact that Kessler had to climb off the canvas himself makes the ending all the more spectacular. A monster left hook connected squarely on Green’s chin, with the American knocked out well before he hit the ground. No count was necessary, as Green immediately clutched his jaw, wondering what the hell just hit him.

Randall Bailey KO11 Mike Jones (06/07/2012) – Any significant fight involving Bailey usually means he boasts little more than a punchers chance to win. That was precisely the case here, as the previously unbeaten Jones was well ahead before getting dropped in the 10th and stopped for good in the 11th round of their vacant alphabet title fight.

Danny Garcia KO4 Erik Morales (10/20/2012) – By his own admission, Garcia showed Morales too much respect in their first fight earlier in the year. The unbeaten Philly boxer knew better than to make that same mistake twice. Morales – overweight in the first fight – tested positive for a banned substance in the days leading up to the rematch. Garcia took his frustrations out on the faded legend, drilling him with a left hook to put him nearly through the ropes to end a career-year on a high note.

Shinsuke Yamanaka KO7 Tomas Rojas (11/03/2012) – A statement fight if there ever was one, as Yamanaka served notice as potentially the best bantamweight in the world. The defending titlist came out with knockout intentions early in the seventh. Three consecutive power punches had Rojas hurt, with a follow-up straight left causing him to pitch forward face first to the canvas.

Gary Russell TKO3 Roberto Castaneda (11/09/2012) –  The fight very much looked like a stud athlete facing an opponent to be announced. Russell dominated the overmatched Castaneda, but at least provided a highlight reel ending. The unbeaten southpaw planted his feet long enough to connect with a right hook that literally folded Castaneda in half as he crumpled to the canvas midway through the third round.

Angelo Santana KO5 Juan Garcia (11/16/2012) – Santana hasn’t allowed a fighter to last the distance in more than three years. Garcia’s night began with upset expectations, but that game plan went violently out the window early on. Santana floored the Michigan native early in the bout, then closed the show in emphatic fashion, with a flurry of punches followed by a straight left to end the night.

Jake Donovan is the Managing Editor of Boxingscene.com. Follow Jake on Twitter: @JakeNDaBox