There are almost too many to choose from but these are the biggest and most important knockouts in MMA history.
When everything is on the line, when it is all or nothing, something must give.
Not just the most brutal and concussive knockouts that the sport has seen, these are knockouts that changed the game. MMA did not look the same after these blows. When these men fell to the floor collapsed, we realized that the landscape of MMA changed, and it was intense.
The top 10 knockouts in MMA history.
The greatest slam knockout of all time. Many people have this as one of the top three KOs of all time.
I, however, disqualify this knockout from my list due to a controversy.
Many have debated that the actual concussive blow came from an incidental and accidental headbutt and that, in my mind, mars the greatness of the moment ever so slightly.
The KO: Jose Aldo came out of the gate and threw a double flying knee, following up with punches, ending the fight in just eight seconds.
Cub Swanson was left in a heap on the ground with major gashes above and below his eye.
The Impact: It was no secret that Aldo was a dangerous fighter, but this brilliant eight-second knockout announced him as the rightful heir to the featherweight crown.
Aldo would win the belt in his next fight and has so far made four successful title defenses.
The KO: Mark Coleman could not put away the young upstart Pete Williams and after over 12 straight minutes of fighting, he had become exhausted.
Backed up against the cage, Coleman was already too tired to comprehensibly defend the kick headed straight toward the front of his face. The kick landed squarely, dropping Coleman into a helpless pile.
The Impact: It was a surprising upset punctuated by the devastating finish. With Coleman being a recognizable figure among fans, it was one of the first major examples of how anything can happen in this sport.
The KO: Chuck Liddell was looking confident and in control as he slowly walked Evans down for much of the first round and the beginning of the second.
Then, in a flash, Liddell threw a lead uppercut that he would eternally regret. Evans threw a massive right hand to Liddell's jaw, that would drop him like a bullet. Liddell collapsed and Evans realized as he was running in that the job was already done.
The Impact: This was the true beginning of the end for Liddell as no one had ever seen him laid out completely unconscious.
It was a shocking sight and it alerted fans around the world that the torch had officially been passed to the new generation of top fighters.
The KO: Champion Rashad Evans decided to play Machida's counter-striking game, and by the end of the first round, it was becoming apparent that Machida was simply better at it.
In the second round, Machida continued to tag Evans, backing him up against the fence. Evans courageously fired back, but it was foolhardy.
As Evans lurked forward, Machida landed one last blow that sent Evans' lifeless body bending awkwardly backwards against the fence in a memorable KO.
The Impact: To this day, it is the only time Evans has ever lost, let alone get knocked out. With such a virtuoso performance to claim the championship, most people thought that Machida would be untouchable for years to come.
The KO: Andrei Arlovski had been controlling the round using good footwork and crisp boxing.
Perhaps getting a little too comfortable, Arlovski backed Fedor Emelianenko up and then surged forward with a flying knee.
With his full wits still about him, Emelianenko timed the counter perfectly with an overhand right that sent the soaring Belarussian to the ground and out cold.
The Impact: Although he had many detractors in America, the legendary Fedor Emelianenko made a huge statement flattening Arlovski, who was ranked in the top 3 in the world.
Fedor's dominance and mystique would fade in his next couple of bouts, but his stunning KO over Arlovski is a potent reminder as to the command he once had over the sport.
The KO: Mirko Filipovic had shut down the aggression and offense of Wanderlei Silva and had begun methodically picking him apart.
While backing him down in the middle of the ring, Filipovic launched his vaunted left high kick and sent Silva crashing to the mat with a gash on the side of his head.
The Impact: This was Mirko "Cro Cop" at the height of his powers as he became the first man to knock Wanderlei Silva completely unconscious.
He would go on later that night to complete and win the prestigious Pride Open Weight Grand Prix, cementing himself as one of the best fighters in history.
The KO: Deep into their war, Wanderlei Silva had begun to slow down while Dan Henderson continued to keep his rhythm.
A bit quicker and more accurate, Henderson engaged Silva in an exchange and landed a devastating left hook that knocked the Brazilian legend cold. In the heat of the moment, Henderson ensured his victory by jumping and landing a brutal right hand on his fallen opponent as the referee dove in.
The Impact: Henderson has had many epic knockout victories, but none are quite as monumental as the day he knocked out Wanderlei Silva and became the first and only man to simultaneously hold two major world titles in different divisions.
The KO: After a slow feeling out process, Vitor Belfort and Anderson Silva began to exchange a couple of quick flurries.
As they reset, Anderson threw a front kick up the middle that landed flush, catching Belfort on the chin and by surprise.
Belfort's body collapsed underneath him and Silva followed up with a few unimpeded strikes on the ground to seal the deal.
The Impact: Silva had looked vulnerable in his last fight and he had already delivered such incredible KOs in the past, that fans were not really sure what else the world's best fighter had to show.
Anderson Silva showed that he is still the world's best fighter and that his quest to continually dominate in spectacular fashion was not over.
The KO: After a hard fought battle for over 13 minutes, Wanderlei Silva was still keeping up his dangerous and aggressive striking against Quinton Jackson.
Jackson started slowing down a little, and as the punishment started piling on, Silva threw a perfect knee from the Thai clinch that rendered Jackson unconscious and left his body dangling between the ropes with blood pouring from his face.
The Impact: This rematch was the height of Silva's dominance and the only time that Jackson has been knocked completely unconscious.
By demolishing Jackson in such brutal fashion, Silva was widely regarded as the most fearsome 205 lb fighter on the planet.
The KO: After dominating most of the first round with ground and pound, Gabriel Gonzaga was stood up by the referee with less than a minute left in the first round.
Facing the most feared striker the sport had ever seen, Gonzaga threw an improbable head kick that slipped past Mirko Filipovic's defense and the legend crumbled instantaneously. Filipovic was unconscious with his ankle grotesquely twisted underneath him.
The Impact: Quite simply, it is likely the most shocking knockout in MMA history. A man known as being far and away the best high kicker in the sport was ironically victimized by his own specialty.
A huge favorite to win the fight and then go on to battle Randy Couture in a super fight, Filipovic was destroyed by a Brazilian jiu-jitsu specialist in the most unexpected manner.
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