Most years, one knockout rises above the rest. A knockout so thunderous, so unexpected, there's hardly any room for debate. Fortunately, six months into 2013, there are at least three or four candidates worthy of entering that discussion, each one supremely violent in their own right. So yeah, it's been a good year.

With that said, there can only be one moment to claim 2013's Half-Year top spot. And for that, we travel back to UFC 156, when two goliaths awoke a fading Las Vegas crowd and reminded everyone what the furious anger of an underdog's justice looks like.

Velasquez reacts to Silva vs. Overeem

This fight was Alistair Overeem's for the taking. Listed as high as a 4-to-1 favorite, "The Reem" scoffed at Antonio Silva for weeks leading up to the event, declaring "Bigfoot" to be a standing target and vowing to make him a mere statistic by the time the dust settled. But when the time came, Overeem's words proved far less prophetic than an innocuous comment made cageside by Joe Rogan midway through round one.

"Alistair's got his hands down, chin up -- not worried at all about ‘Bigfoot.'"

The strategy worked, right up until the moment it didn't. As Silva gazed across the Octagon, entering the final frame down 2-0 on the judges' scorecards, images of a sneering Overeem flashing through the giant's mind, something snapped inside. "Bigfoot" stormed out to meet Overeem in the center of the cage, broke off the clinch and unleashed a feverish salvo. Hooks, uppercuts, head kicks; everything was in play. 530 pounds of force colliding together in a morbid ballet.

Overeem wilted backwards against the fence, trapped, his legs trembling. Fueled by rage and revenge, Silva unloaded every ounce of himself into his punches. Right hook, right hook, uppercut, uppercut; 15 brutal, unanswered shots in all. One final right hand and Overeem collapsed onto the canvas, no clue of what just transpired -- but "Bigfoot" wasn't done. The Brazilian tossed referee Herb Dean aside and roared back into Overeem's bewildered face. His message was clear. This was personal.

Dean eventually peeled Silva away, while everyone within 100 feet of the Octagon peeled their collective jaws off of the floor. This sport, man, sometimes it's wild.

2. Vitor Belfort vs. Luke Rockhold -- UFC on FX 8

It's one thing to knock your opponent out in spectacular fashion. But it's another thing altogether to do it so spectacularly, and so implausibly, that even the guy on the receiving end can't believe what just happened. And to that, we move onto No. 2 of our list, which easily could be No. 1 depending on your mood or which day on the week it is.

Vitor Belfort vs. Luke Rockhold

UFC on FX 8's main event was supposed to be Luke Rockhold's stepping stone to glory. With a likely title shot on the line, the final Strikeforce middleweight champion walked across those Octagon steps for the first time, past the shadows of vanquished warriors and right into the bloodstained den of the Old Lion. A veteran of the game from the NHB days, Vitor Belfort's lengthy résumé and otherworldly physique did little to sway the minds of Las Vegas oddmakers, who once again pinned the Brazilian as an underdog within his home country. Though that slight didn't mean much once those cage doors swung shut.

Rockhold's ill-fated UFC debut lasted just two-and-a-half minutes before Belfort ended the night so easily, and so abruptly, that his fallen foe, incredulous at what just transpired, perhaps summed it best. "I'm speechless. I don't know... He hit me with a spinning heel kick."

3. Mark Hunt vs. Stefan Struve -- UFC on FUEL TV 8

If this was a list called ‘Knockout that Spawned the Most Brutal Photograph of 2013,' then this gem would take the top spot, and it wouldn't even be close.





Josh Hedges, Getty Images via Zuffa LLC

There's no sight as perversely entertaining as heavyweight MMA when it borders on exhaustion. And that's exactly where we were entering the final round of UFC on FUEL 8's co-main event -- scorecards tied at one apiece, both goliaths sucking down deep gasps of air. It was left to the age-old question of who could dig deeper. But Mark Hunt was born down. You know this.

One huge overhand right crashed upon the brow of Stefan Struve, sending the 7-footer from the Netherlands reeling backwards across the cage. Then came another, and another. The crowd swelled, the ghosts of Saitama Super Arena roaring back to life one last time in support of the "Super Samoan." Then it happened. A monstrous left hook hammered into Struve's jaw, snapping the bone, hurtling the bloodied youngster down onto the canvas. Hunt just walked away, not even gazing upon his handiwork, before reluctantly sauntering back to finish the job. But it was already over. The Japanese crowd exploded, raining a decade's worth of adulation down on Hunt, who simply raised his arms in triumph, victorious once more.

4. Junior dos Santos vs. Mark Hunt -- UFC 160

"The Super Samoan" makes a second appearance on our list, though this time not in a way he'd hoped. For many, Junior dos Santos vs. Mark Hunt was the real main event of UFC 160. A salivating proposition made possible only by a late injury withdrawal and renewed campaign to #RallyForMarkHunt, fight fans finally got to see the clash of titanic sluggers they'd been clamoring for, and just like we all knew it would, the battle lived up to its lofty expectations.

Junior dos Santos vs. Mark Hunt

For the better part of three rounds, dos Santos and Hunt traded behemoth punches with reckless abandon. Dos Santos uncorked an atomic bomb of an overhand right to drop Hunt early in the first, but Hunt, in classic Hunt fashion, gamely gritted his teeth and trudged back into the pocket, staggering dos Santos with a left hook against the fence in the second.

With the grueling 14-minute brawl nearing its final horn, and "Cigano" up mightily on the judges' scorecards, most fighters would be content to ride out their victory to the bell. But dos Santos, the former heavyweight champion on a mission to reclaim what once was his, isn't most fighters. Employing grace unnatural of a 240-pound man, dos Santos launched into a spinning wheel kick that clipped the top of Hunt's head, sending the K-1 veteran crashing to the mat, where he promptly ate another huge right hand. "Unbelievable!" Joe Rogan screamed ringside, while a frenzied dos Santos leapt out of the Octagon to shake Mike Tyson's hand, before joyously declaring, "I won!" Indeed he had.

5. Emanuel Newton vs. Muhammed 'King Mo' Lawal -- Bellator 90

Perhaps in no other sport is the underdog's résumé so littered with shock-the-world moments. It's one of the reasons MMA is beloved by those who follow it. With countless ways to win, anything truly is possible -- even a spinning back fist from a career journeyman.

Emanuel Newton vs. Muhammed Lawal

Muhammed "King Mo" Lawal was Viacom's golden goose. A charismatic free agent acquisition with a marketable persona, championship pedigree, and the skills to boot. It was only inevitable before Lawal became Bellator's light heavyweight champion, and ultimately, the face of the organization. But fate, thy name is Emanuel Newton.

An unheralded veteran with a proclivity for hardcore music, Newton was an afterthought, a stepping stone to Lawal's eventual destiny. Yet all the hype in the world couldn't keep Lawal's hands up, and following an exchange early in the first round, Newton whirled around and planted his meaty left paw straight into the cheek of the King. Lawal went limp, tumbling into the awaiting arms of Newton, who locked in the beginning stages of a rear-naked choke before realizing that his job was already done. Just like that, the King was dead, and the story of "The Hardcore Kid" had begun.

Honorable Mentions

Wanderlei Silva vs. Brian Stann -- UFC on FUEL TV 8

Anthony Pettis vs. Donald Cerrone -- UFC on FOX 6

TJ Grant vs. Matt Wiman -- UFC on FOX 6

Collin Reuter vs. Gerald Fike -- SAARFC 2 (Video)

Ramsey Nijem vs. Myles Jury -- UFC on FOX 7

Josh Thomson vs. Nate Diaz -- UFC on FOX 7

Note: Since Uriah Hall vs. Adam Cella technically took place in 2012 in a exhibition bout, it was not available for consideration.