Everyone loves a good knockout, and MMA is no stranger to providing fans with them. The greatest thing about a knockout is it can turn a fight the other way in a blink of an eye. One punch can change history, and the ones on this list have done just that.
It's not easy putting together a list of the top 25 UFC knockouts of all time because there have been so many memorable moments featuring fans' favorite fighters. Still, there are some that stand out above all the rest and are more significant than others.
Whether they come in the opening seconds or the final minute, they are the part of the fight fans most remember.
Pedro Rizzo was 11-1 in MMA and going up against a young Josh Barnett. Rizzo was known for his brutal leg kicks and stand-up skills, but his opponent was undefeated.
It would be one of the best fights ever to take place in the UFC before the Brazilian finished off the 23-year-old in the second round with one punch.
This would be the knockout that got Rizzo a title shot against Randy Couture. He lost a controversial unanimous decision over five rounds of back-and-forth action.
If fans ever wondered why Matt Hughes was known for his slams, this is why.
It didn't go without controversy, as the new welterweight champion knocked himself unconscious for a brief moment after bouncing Carlos Newton's head off the canvas from the top of the cage at UFC 34.
Hughes would go on to defend the title five times before losing it to BJ Penn at UFC 46.
Former UFC Lightweight Champion Jens Pulver went into this comeback fight as a 7:1 favorite over Joe Lauzon.
The 21-year-old UFC newcomer was not expected to take out the veteran, but he did and did it in just 47 seconds. It was one of the biggest upsets in the sport and remains one till this day.
Jackson was coming off a defeat to Forrest Griffin in a title match for his light-heavyweight belt. Now, he was getting his chance to return at UFC 92 against his greatest rival, Wanderlei Silva.
Silva had owned two victories over Jackson prior to their third and final bout.
Three minutes into Round 1, Jackson connected with a left hook that put the Brazilian legend to sleep.
Mark "The Hammer" Coleman, the father of ground-and-pound, was a two-time UFC tournament champion and former UFC heavyweight champion.
He had lost the title to Maurice Smith before he took on Pete Williams. Twelve minutes into Round 1, Coleman's cardio got the best of him again, and Williams took advantage with a head kick that put him out against the cage.
Nobody saw this one coming. It was supposed to be the fight that set up a fight between Chuck Liddell and light-heavyweight champion Forrest Griffin.
Rashad Evans put an end to that in the second round when he landed a right hand that put the Iceman to sleep. This would be the first of three consecutive knockout losses for the former light-heavyweight champion.
The Ultimate Fighter winner Rashad Evans hadn't thrown many, if any, head kicks at all in his career. The one he threw at UFC Fight Night 8 definitely counted.
It wasn't without a little trouble from Sean Salmon, who was a credible wrestler and gave Evans problems early. It would be the first of many impressive knockouts in Evans' career and the first of many disturbing knockouts for Salmon.
In a fight that Matt Serra was winning decisively, Shonie Carter waited until the last 10 seconds of the fight before he threw a spinning-back fist that knocked out the unbeaten fighter from New York.
These types of knockouts are almost unseen in MMA, but Carter's still remains to this day one of the most celebrated.
Quinton Jackson had done it four years earlier, but could he do it again against the one of the most dominant light-heavyweight champions of all time?
Liddell had gone 7-0 since his first loss to Jackson at Pride Final Conflict in 2003, including four title defenses.
Jackson was coming in with a 26-6 overall record and wasted no time in knocking out Liddell one minute into the first round.
In 44 seconds, a young 21-year-old Brazilian named Vitor Belfort made his mark in the UFC with this defining win early in his career.
He had previously fought Randy Couture, Tank Abbott and Tra Telligram, but this would be the one that fans always look back on as one of his best knockouts because his opponent was the ferocious Chute Box fighter, Wanderlei "The Axe Murderer" Silva.
There had to be at least one flying-knee knockout on this list, and the one James Irvin knocked Terry Martin out with at UFC 54 is the best. Other flying-knee knockouts include Spencer Fisher vs. Matt Wiman and Fredson Paixao vs. Pablo Garza.
The referee had waved both fighters in for the second round. Irvin met Martin in the middle, but not with his fists. He threw a flying knee that put Martin out immediately.
It would be the first of two very memorable knockouts for pound-for-pound king Anderson Silva against one of the greatest middleweight champions in Rich Franklin.
The first was for the middleweight championship that Franklin had defended numerous times. Silva was coming off a first-round knockout victory over Chis Leben.
After a brief feeling-out process, Silva got Franklin against the cage and into his Muay Thai clinch, where he began to deliver knee after knee to Franklin, breaking his nose in the process.
This was the second of two consecutive knockout wins over UFC lightweights for BJ Penn.
Three fights into his career, the 23-year-old from Kailua, Hawaii was matched up with Japanese fighter Caol Uno. Eleven seconds into Round 1, it was over. Penn had knocked out Uno for the first time in his career.
Their first fight was nothing but controversial after five rounds of back-and forth mixed martial arts action that saw Lyoto Machida take a unanimous decision and extend his undefeated record.
The rematch was quickly set for UFC 113 in Montreal, Canada. Rua came out with a different game plan consisting of attacking with the hands instead of his kicks. It paid off, and he knocked Machida out halfway through the first round.
This 13-second knockout is one of the most unique in MMA. Gary Goodridge made his debut against Paul Herrera and didn't take any time in dispatching his opponent with an elbow attack that will go down in history as one of the best.
Goodridge made it past the semifinals of the UFC 8 tournament but was submitted by Don Frye in the finals.
This unforgettable knockout occurred at UFC 49, an event filled with notable knockouts. Yves Edwards took on the tough lightweight fighter Josh Thompson in the first bout of the evening.
Edwards had already fought professionally over 35 times, and he showed the skills he had learned and a new one—a spinning back kick while his opponent had a clinch around his back.
It was supposed to be Anderson Silva's toughest test to date as far as striker vs. striker matchups go. Vitor Belfort was coming off a long layoff, but he was also coming off a three-fight knockout streak over Rich Franklin, Matt Lindland and Terry Martin.
Silva delivered one of the most brutal front kicks you will ever see in the very first round of the title fight, putting Belfort down and out for the first time in his career.
It was the first time two undefeated fighters were going to meet for a title fight. Lyoto Machida was 14-0 going into his light-heavyweight title fight with Rashad Evans, who was 13-0-1.
Machida put Evans down in the first round but was not able to finish. What he did, though, was establish a fighting style that nobody could figure out, and Evans didn't know what to do.
He dropped Evans again in the second round and was able to finish him this time with a standout performance of accurate striking and power.
This come-from-behind knockout over one of MMA's most physically imposing fighters is one of the most memorable victories ever.
Mike Russow had accepted everything Todd Duffee had to offer in the first two-and-a-half rounds except being knocked out. In the third round, Russow connected on the undefeated heavyweight and put him to sleep.
Everyone remembers Phil Baroni's famous post-fight quotes versus Dave Menne, but the knockout was just as awesome.
Within one second of getting the first and former middleweight champion hurt and against the cage, Baroni delivered five more punches in one second to put his opponent out.
Tank Abbott will go down as a fan favorite fighter because of his knockouts and fearless fighting spirit.
This was his second fight at UFC 6: Clash of the Titans. It took 18 seconds before the Huntington Beach fighter brutally knocked out John Matua in one of the most disturbing knockouts ever witnessed inside the Octagon.
This mind-blowing moment came at The Ultimate Fighter 4 Finale. Scott Smith was known for his toughness and "hands of steel," but his opponent, Pete Sell, was also a hard puncher.
After digging in a body shot to his former teammate from The Ultimate Fighter, Smith was visibly hurt and crouched over. Sell shot in for the finishing blow but got hit with a punch he never saw coming and was knocked out.
Gabriel Gonzaga's head kick over Mirko Cro Cop was just as savage as any head kick the former kickboxer had delivered before. It was supposed to be the fight to set up Cro Cop vs. Couture for the heavyweight championship, but Gonzaga got the shot instead because of his sensational performance that night at UFC 70.
This head kick started the downfall of the legendary Pride fighter and would be the start of many more to come.
Michael Bisping's trash talk leading up to the UFC 100 bout was not answered by Dan Henderson, at least not until they met in the cage.
Henderson showed early that the fighter from England wasn't going to be much of a challenge as he defended takedown attempts and hurt his opponent early.
In the second round, Henderson delivered his H-bomb and put Bisping to sleep. He also followed up on it in what was arguably the best moment of his career.
Chuck Liddell was looking to reclaim the light-heavyweight title he had lost to Randy Couture two years before. The rematch was announced for UFC 52, which took place one week after the historic battle between Forrest Griffin and Stephan Bonnar.
It only took two minutes before Liddell connected with his trademark right hand on Couture's chin, putting the two-time UFC champion to sleep.
Liddell would go on to knock out Randy Couture for a second time at UFC 57, but the first knockout was his biggest moment.