UFC has come a long way since its early inception. Gone are the grueling exhibitions featuring fighters from different weight classes participating in fights with very relaxed rules.

The no holds barred style brought a great deal of trouble for UFC from state legislators. Eventually, UFC would introduce more stringent rules and more narrow weight classes. One might expect these changes to cause a downward swing in popularity for the premiere MMA promotion. However, UFC began gaining popularity because of an evolution in mixed martial arts itself. The varying weight classes ushered in an advent of styles deviating from the old wrestling and jiu-jitsu laiden bouts.

As the sport evolved, fighters did as well. We began to see more well trained, disciplined athletes. The rise of striking and kickboxing added an element to fights which gave way to powerful strikers like Mirko Cro Cop, Chuck Liddell, and many others.

The pace of fights was quickened exponentially and we began seeing more KO finishes. It's no secret that UFC fans and all MMA fans alike grew rabid in anticipation of the brutal style of stand up combat that was so popular in Pride Fighting Championship.

Sometimes, an expert striker can end a fight only seconds after the first bell. While some may feel they're being cheated out of a long competitive match, it seems popular opinion leans toward seeing a few heavy bangers followed by resounding knockout strikes.

It's time to take a look at the 15 fastest knockouts in UFC history. These finishes, separated by mere seconds, all tell their own story. Join us as we take a look at each individual light speed bout. We begin our countdown with an impressive KO involving UFC legend Andrei Arlovski

16 T15. Andrei Arlovski vs Paul Buentello 

Bout length: 15 seconds

Andre Arlovski headed into UFC 55 as the Undisputed Heavyweight Champion after Frank Mir was put on the shelf due to a motorcycle accident. His first Undisputed title defense pitted him against Paul Buentello, a Heavyweight competitor coming in on a six fight win streak.

Many viewed Arlovski as an underdog in this endeavor due to the dominance Buentello had exhibited in fights leading up to the event, including a first round win over Kevin Jordan at UFC 53. However, his meeting with "The Pitbull" would mark the end of his dominant run when Buentello threw a sloppy right cross to be countered with a simultaneous right cross of Arlovski's own.

This marked the beginning of the end for Buentello as he would fight only one more fight in UFC before moving onto brief stints in Strikeforce and Affliction. He would later return to UFC and receive two devastating defeats, losing to Stefan Struve and Cheick Congo, marking his final run in UFC.

Also noteworthy, Arlovski's KO victory over Buentello would be his final Heavyweight Title Defense after losing to Tim Sylvia at UFC 59.

15 T15. Jens Pulver vs John Lewis 

Bout Length: 15 seconds

There was little doubt that John Lewis was out of his league as he stepped into the octagon to take on Jens Pulver. Pulver, a rather decorated MMA fighter, had won several championships both in UFC and various other MMA promotions.

John Lewis entered UFC 28 fresh off his fist and only UFC victory. His fight with "Lil Demon" would also serve as his last fight in UFC. Pulver's left cross that lead to his 15 second first round victory would also retire Lewis from MMA as a whole.

However, the future would hold a different card for Jens,as he went on to become the first ever Lightweight Champion in in UFC history.

14 14. Terry Martin vs Jorge Rivera 

Bout time: 14 seconds

Terry Martin is one of the most experienced athletes in the world of professional fighting. He holds a professional boxing record of five wins and a single loss, with those five victories coming via knockout. He also holds a professional mixed martial record of 22 wins and 11 losses. It's safe to say he has seen his fair share of action.

Jorge Rivera wasn't exactly green as he boasts a professional MMA record of 20 wins and 9 losses.

So, what happens when two high caliber veterans meet up? Well, the answer is not much. The ticket holders for UFC 67 were treated to a first round knockout after a whole 14 seconds. By no means was this fight a technical masterpiece, but people got what they paid for, a massive knockout from one veteran to another.

13 13. Anthony Johnson vs Chad Reiner 

Bout length: 13 Seconds

The left hook told the tale of this one. Anthony Johnson, making his UFC debut on a televised UFC Fight Night program, beat Chad Reiner in only 13 seconds. This marked the beginning of a successful career for Johnson and sent fellow rookie Reiner back to the minors, so to speak. In fact, this was the second and final UFC fight of Reiner's career. Johnson has gone on to achieve a 20-5 record to date and also won KO of the night honors for this fight.

Johnson's two punch KO on Reiner was the start of a terrific career for "Rumble." Although he never won any championship gold in UFC, his career may just be considered Hall of Fame worthy.

12 12. Gary Goodridge vs Paul Herrera 

Bout length: 13 seconds

In a UFC throwback, dating back to UFC 8, we saw Gary Goodridge defeat Paul Herrera in the early rounds of a contest in an eight man tournament. The one night tournament style was one of the highlights of the early UFC days and this bout proves why.

Knockout victories were fewer and further between in the early days of UFC, making them all the more exciting to see.

Goodridge managed to lock Herrera in the crucifix position, a hold rarely seen in modern mixed martial arts. The crucifix leaves a fighter in a very vulnerable position. From there, Goodridge saw an opening to land various elbows, leaving Herrera completely unconscious. The beating Herrera received was so brutal, that he was out of commission and unable to fight for several years after the bout.

11 T10. Johny Hendricks vs Jon Fitch 

Bout length: 12 seconds

Jon Fitch was given the ultimate opportunity to battle for an interim UFC Welterweight championship with George St.Pierre sidelined due to a knee injury. Fitch himself was coming off a 10 month hiatus after recovering from a shoulder injury of his own. Fitch's last bout prior to injury was a draw with B.J. Penn. All things considered, Fitch was still heavily favored to defeat Hendricks.

In a sport where anything can happen, Fitch's odds seemed to plummet. They plummeted in a matter of 12 seconds to be exact. Hendricks threw a left hand that would be Fitch's undoing, knocking him out cold.

10 T10. Rob Emerson vs Manny Gamburyan 

Bout length: 12 seconds

In a battle of the relatively unknown Ultimate Fighter contestants, we saw one of the strangest knockouts in UFC history. At UFC 87, Rob Emerson would find himself in a battle with Manny Gamburyan of The Ultimate Fighter Fame.

After a brief exchange of a few punches, Manny stumbled a bit and landed on his back. Emerson saw the opportunity and slid in with a few hooks before a devastating haymaker put Gamburyan out cold.

Many say the win was a fluke and that Gamburyan could have beaten Emerson handily. All that really matters is what happens in the end and Emerson won the fight.

9 T8. Duane Ludwig vs Jonathan Goulet 

Bout length: 11 seconds

Here is a fight that could be higher on the list, but due to an official ruling by Dana White, it's staying where it is. According to a Nevada State Athletics commission official, the bout lasted 11 seconds when evidence suggested the fight actually ended in six seconds.

It was a mere timekeeper error that doesn't do the fight justice, but that's neither here nor there. Ludwig lander a counter punch immediately as the fight started, sending Goulet down to the mat. Sadly, the original ruling was not overturned and the six second knockout will forever remain the 11 second knockout. The matter of seconds doesn't change the quality of the knockout.

8 T8. B.J. Penn vs Caol Uno 

Bout length: 11 seconds

B.J. Penn is regarded as one of the greatest to ever step foot in the Octagon. He holds the illustrious accolade as a member of the UFC Hall of Fame. He is one of only two men in UFC history to hold both the UFC Lightweight and Welterweight championships.

Caol Uno is no slouch in the MMA world, accumulating an impressive and lengthy record of 32 wins and tallying 18 losses.

Penn, showing no apparent fear or hesitation, rushed Uno and dropped him with an uppercut. Uno was definitely out of commission after the punch as Penn stood over him delivering a few insurance punches to stop the fight. The two would meet again a year later, fighting to a draw.

7 7. Mark Weir vs Eugene Jackson 

Bout time: 10 seconds

If you're going to win just one fight as a UFC competitor, it's ideal that you win it in style. This was the case when Mark Weir faced Eugene Jackson in his UFC debut. Weir had already accumulated a winning professional MMA record prior to his UFC 38 contest with Weir, thus earning himself a fight on the main card at a major UFC event.

Weir managed to land a nice counter jab after a missed kick by veteran Jackson, which would send Jackson to the ground. A few seconds of solid ground and pound by Weir and the fight was called. Jackson appeared to be on another planet when the decision was announced. He was rocked pretty hard.

Weir enjoyed the moment while it lasted, but he would go winless for the remainder of his UFC career.

6 6. Gray Maynard vs Joe Veres 

Bout length: 9 seconds

Gray Maynard is hands down one of the greatest Lightweight fighters of all time, holding wins over other greats including Clay Guida, Frankie Edgar, Nate Diaz, and Kenny Florian, among others.

Joe Veres wasn't exactly met with the welcome wagon upon arriving in UFC as Maynard would be his inaugural opponent. The nine second bout consisted of Maynard approaching Veres and landing a powerful left hook that left Veres seeing stars. Veres competed in one bout following the defeat at the hands of Maynard.

It's noteworthy that this is the only fight in Marnard's career to end with a stoppage.

5 T4. James Irvin vs Houston Alexander 

Bout length: 8 seconds

This incredible knockout was somewhat of a bad omen for James Irvin. It was a spectacular superman punch out of nowhere that left Houston Alexander flat on his back. However, it would also serve as Irvin's final victory in the UFC. Alexander himself, also failed to earn victories in his next two UFC bouts. Keep in mind, at this point neither Irvin or Alexander had been involved in a fight that saw the second round.

Neither fighter went on to be victorious in any of their respective bouts after this squash at UFC Fight Night 13.

4 T4. Don Frye vs Thomas Ramirez 

Bout length: 8 seconds

Don Frye is one of the most iconic tough guys to ever grace the octagon. We all remember his epic battles in Pride Fighting Championships where he showed how much of an all around tough guy he really is. However, let's look back at his first career first at UFC 8, where Don Frye KO'd Thomas Ramirez with a right  hook, ending Ramirez's UFC career.

Frye would go on to have a historic UFC career with a record of 15 wins and one, lone loss.

3 T1. Ryan Jimmo vs Anthony Perosh 

Bout length: 7 seconds

Although Ryan Jimmo may seem like a relatively unknown entity, he had a great career for himself in the now defunct Maximum Fighting Championship. In MFC, Jimmo holds the record for most fights and is a former Light Heavyweight Champion.

It would be in his UFC debut at UFC 149 that he would meet octagon veteran Anthony Perosh. Jimmo's debut would be short lived as he threw a right cross that would see Perosh go unconscious before he even landed on the mat, solidifying this as one of the fastest KOs in UFC history.

2 T1. Chan Sung Jung vs Mark Hominick 

Bout length: 7 seconds

Considering how uncommon knockouts are in the UFC Featherweight division, Chan Sung Jung delivered one of the most emphatic victories in the history of the division. Sung Jung threw a solid counter punch against Hominick's first strike of the bout, knocking him out cold. This would be the precursor to the demise of Hominick's career.

Not only does Sung Jung have one of the greatest knockouts in UFC history, he also has the distinction of having one of the greatest nicknames, "The Korean Zombie."

Sung Jung earns the nickname due to his granite jaw, raw punching power, and aggressiveness.

1 T1. Todd Duffee vs Tim Hague 

Bout length: 7 seconds

If you were to create a fighter in a laboratory, chances are he would come out looking like Todd Duffee. Add a unique athleticism and a ton of heart to his statuesque frame, and you have one of the more intimidating looking, powerful UFC competitors of all time.

Duffee's amazing defense wouldn't need to be employed when he faced Tim Hague at UFC 102. Duffee refused to touch gloves with Hague prior to the fight, which seemed to upset Hague. He stormed at Duffee with a wild left hand, leaving himself open for a jab from Duffee. Hague was out cold.

Despite a recent loss to Frank Mir, Duffee is still a top Heavyweight and with knockout power like he displayed in this fight, there is no question as to why.