Twenty-five years ago last November, combat sports changed forever. Eight individuals from different fighting disciplines met in a tournament at McNichols Sports Arena in Denver to see whose martial art was supreme. Called "The Ultimate Fighting Championship," the event involved a sumo wrestler, a boxer, a Brazilian jiu-jitsu practitioner and everyone in between. In the end, the smallest competitor -- Royce Gracie -- proved size did not matter as he dominated the competition with elite grappling skills.

Flash-forward to today, and the UFC is no longer a small organization encouraging "no-holds-barred" fighting. Dana White, Lorenzo Fertitta and Frank Fertitta purchased it in 2001 for $2 million and sold it last year for more than $4 billion. Boasting some of the most talented mixed martial artists in the world, the UFC is one of the fastest-growing promotions in sports.

How did it get to this level? ESPN's MMA team -- Brett Okamoto, Ariel Helwani, Gilbert Melendez, Chamatkar Sandhu, Greg Rosenstein, Jeff Wagenheim, Phil Murphy and Eric Tamiso -- voted for who they believed was most responsible for this success over the years.

Dana White (along with Lorenzo and Frank Fertitta) purchased the UFC in 2001. Jeff Bottari/Zuffa LLC/Getty Images

T-1. Dana White, UFC president

If you speak to anyone outside the MMA bubble and ask them about the UFC, they likely know who White is. He's the face of the organization, the carnival barker, convincing you to tune in week in, week out, and spend your money on a monthly PPV. He is to the UFC what Vince McMahon is to the WWE. He's the promoter and one of the best to ever do it.

When you talk about influence, it doesn't get any more influential than being able to convince a friend to make a financial investment in a cage fighting organization -- when the sport was on the verge of collapse, no less. That's what happened in 2001, when White asked his friend Lorenzo Fertitta and brother Frank to acquire the UFC from Bob Meyrowitz. And the rest, as they say, is history.

When MMA was seeking to gain mainstream acceptance, White was on the road preaching to anyone who would listen, and educating them about this sport. When he's firing on all cylinders, White has the ability to get you emotionally invested in a fight, a fighter and a card. Whatever he's selling, more often than not, you're buying it. It's because of his passion, which comes through in spades.

-- Sandhu

Lorenzo Fertitta, one of the primary owners of the UFC, bought the organization in 2001 for $2 million and sold it for more than $4 billion in 2016. Zuffa LLC

T-1. Lorenzo Fertitta, former UFC CEO

The UFC does not exist as it does today without Fertitta. Plain and simple. White has always been the man front and center, but from 2001 to 2016 (when Fertitta sold the UFC to WME/IMG), his financial commitment and business influence transformed the UFC from a failing sideshow into a global brand.

-- Okamoto

Royce Gracie, bottom, claimed three of the first four UFC tournaments with his elite jiu-jitsu skills. Evan Hurd/Sygma/Sygma/ Getty Images

3. Royce Gracie, first UFC champion

Gracie was not only a major influencer in the UFC, but in martial arts around the world. He was the first real representative of Brazilian jiu-jitsu on a major stage. Though the UFC evolved greatly and now features the best mixed martial artists, UFC 1 was created to definitively prove the best martial arts form. On that stage, Gracie at just 175 pounds beat guys who weighed more than 240 pounds. In fact, he won three of the first four tournaments. This showed that jiu-jitsu, solo, could work against anyone. Gracie influenced generations of fighters. Brazilian jiu-jitsu is not just a martial art but an entire culture and lifestyle.

-- Melendez

Art Davie is one of the co-founders of the UFC, which debuted 25 years ago today. Ethan Miller/Getty Images

4. Art Davie, UFC co-founder

If you ask former referee "Big" John McCarthy who came up with the idea for the UFC, he would say it was Davie. Davie partnered with Rorion Gracie to develop his vision for what the promotion came to be in 1993. He co-owned the UFC until 1995 and was the first matchmaker, staying in that role until 1997. Earlier this year, Davie was inducted into the UFC Hall of Fame for his efforts, with White saying, "Art's contributions to UFC helped lay the foundation for the sport that fans around the world see today."

-- Tamiso

Conor McGregor has headlined four out of the six highest-selling UFC pay-per-view events. Al Bello/Zuffa LLC/Getty Images

5. Conor McGregor, former UFC lightweight and featherweight champion

The biggest draw in the history of the sport. What a run it has been for the Irishman since he joined the UFC in 2013. From knocking out Jose Aldo in 13 seconds to becoming the UFC's first double champion to willing the Floyd Mayweather Jr. fight into existence, McGregor's brief UFC run has been nothing short of astounding. And his greatest impact on the sport won't be anything he does in the cage. It will be his efforts to change the way fighters view themselves and their worth.

-- Helwani

Chuck Liddell claimed the UFC's light heavyweight title in 2005 and held it for more than two years. Josh Hedges/Zuffa LLC/Getty Images

6. Chuck Liddell, former UFC light heavyweight champion

Before social media was what it is today, you really had to be someone special to stand out from the pack of fighters on the UFC roster. "The Iceman," with his iconic blue shorts, mohawk haircut, Japanese writing tattoo on his head (of course), and that stone-cold stare he'd make on his way to the Octagon was exactly that.

During his time with the UFC, he became the first fighter to grace the cover of ESPN The Magazine, and he made guest appearances on television. While it might seem commonplace to see fighters make similar appearances on late-night shows and series now, Liddell was one of the first to do it.

It also didn't hurt his popularity that he was part of one of the hottest rivalries in UFC history. His fights against Tito Ortiz were box-office successes. UFC 66: Ortiz vs. Liddell II was the first pay-per-view in company history to surpass 1 million buys, and it's no surprise the two are set to duke it out one more time later this month.

-- Sandhu

Ronda Rousey was the first female fighter signed by the UFC. Harry How/Getty Images

7. Ronda Rousey, first UFC female fighter

A true pioneer in the sport, Rousey was the first female fighter -- and UFC champion -- in the promotion's history. It wasn't about Rousey's success as much as how she defended her women's bantamweight belt. Rousey won her first 12 professional fights, 11 of which came in first-round finishes. After claiming the title in 2012, she defended it six consecutive times.

Rousey became the face of MMA for multiple years based on her ability to win inside the Octagon and market herself outside it. She trash-talked her opponents like few before her. Her patented scowl during fight introductions was unmistakable. Rousey also promoted the UFC while acting in commercials and making public appearances. Her overall legacy will take a hit because of how her career ended. She was knocked out twice and refused to compete again in the Octagon, leaving the UFC and signing with the WWE in 2018. But despite her controversial exit, Rousey changed the image of female fighters and paved the way for generations to come.

-- Rosenstein

Rorion Gracie, middle, a co-founder of the UFC, was influential in introducing Brazilian jiu-jitsu to the United States. Tibrina Hobson/Getty Images

8. Rorion Gracie, UFC co-founder

Rorion Gracie is the eldest son of Helio Gracie, patriarch of the first family of Brazilian jiu-jitsu. Rorion started training as a youth in Rio de Janeiro, and when he moved to Southern California in the late 1970s, he began teaching jiu-jitsu out of his garage. One of his students was an advertising executive named Art Davie, who became fascinated by Rorion's stories about the Gracie Challenge -- in which family members invited martial artists from other disciplines to try to get the better of Gracie jiu-jitsu in a fight (they seldom succeeded). With that no-holds-barred concept in mind, Davie and Gracie came up with the idea for a competition called War of the Worlds, which they took to the pay-per-view TV company Semaphore Entertainment Group. The name eventually was changed to the Ultimate Fighting Championship.

-- Wagenheim

Bob Meyrowitz is one of the co-founders of the UFC. Ed Mulholland/Zuffa LLC/Getty Images

9. Bob Meyrowitz, UFC co-founder

Meyrowitz said yes. As founder and president of the Semaphore Entertainment Group, he was a pioneer in pay-per-view television, producing mostly music and comedy acts. SEG's one big venture into the sports world had been its presentation of a tennis exhibition between Jimmy Connors and Martina Navratilova. Then one of Meyrowitz's executives, Campbell McLaren, pitched to him a martial arts tournament called War of the Worlds (which had been pitched to McLaren by Rorion Gracie and Art Davie), and the decision-maker was intrigued. He and his team tweaked the concept a bit, including changing its name to the Ultimate Fighting Championship, and Meyrowitz said yes to get the ball rolling.

-- Wagenheim

Campbell McLaren came up with the controversial slogan "There Are No Rules" for the first UFC event. Ethan Miller/Getty Images

10. Campbell McLaren, UFC co-founder

McLaren, one of the founders of the UFC, was the main person to take this from the "fight" business to the "entertainment" business. He recognized that from the beginning. In hopes of drawing as many fans and viewers as possible to the inaugural UFC event 25 years ago, he came up with the slogan "There Are No Rules." His team -- specifically Jason Cusson -- helped develop the exact shape of the cage still being used today. While other founders such as Rorion Gracie focused on finding competitors and setting matchups, McClaren is responsible for making the event a must-see viewing experience. His influence on the promotion cannot be overstated.

-- Melendez

Frank Fertitta, along with his brother Lorenzo and Dana White, purchased the UFC in 2001. Zuffa LLC

11. Frank Fertitta III, Founder of Zuffa, LLC

Fertitta is CEO of Station Casinos, which owns and operates numerous casinos, mostly in the Las Vegas area. In 2001, he and his younger brother, Lorenzo, created a company called Zuffa (Italian for "fight"), which became the parent entity for the UFC when they bought the fight promotion for $2 million. In 2016, Zuffa sold its majority stake in the UFC to an investment group headed by WME-IMG (now called Endeavor) for $4.2 billion.

During the Fertitta ownership era, Frank was a far less prominent figure than his brother, who served as CEO. But Frank was a fixture at cageside for big fights, and Conor McGregor loved to name drop "Uncle Frank" for the postfight whiskey toasts they shared.

-- Wagenheim

Tito Ortiz held the UFC's light heavyweight title from 2000 until 2003. AP Photo/David Becker

12. Tito Ortiz, former UFC light heavyweight champion

The Huntington Beach Bad Boy. Ortiz wasn't the first UFC fighter to turn himself into a "character," but he might have been the first to perfect it. His rivalry with Chuck Liddell and the boss himself, Dana White, were great for business. And as much attention as Ortiz gets for his personality, he was a legitimate talent in one of the sport's premier divisions.

-- Okamoto

Georges St-Pierre is one of only five fighters to win a title in two different classes. Jeff Bottari/Zuffa LLC/Getty Images

T-13. Georges St-Pierre, former UFC welterweight and middleweight champion

Tiny Saint-Isidore, Quebec, can't claim much, but it can proudly claim to be the birthplace of arguably the greatest fighter of all time. Not only has St-Pierre avenged his only two losses, he is one of only five fighters to win a title in two different classes. More impressive, he's the rare combat sportsman who just might retire on a winning streak and as a champion. Very few in either boxing or MMA can claim that. And unlike Anderson Silva or Jon Jones, he doesn't have any PED blemishes on his résumé.

-- Helwani

Marc Ratner is the former executive director of the Nevada State Athletic Commission. Ethan Miller/Getty Images

T-13. Marc Ratner, UFC vice president of regulatory affairs

It might not have received much fanfare at the time, but in hindsight, hiring Ratner away from the Nevada Athletic Commission in 2006 could have been the shrewdest move Lorenzo Fertitta and the UFC ever made. Ratner, in essence, was responsible for getting the sport of MMA legalized throughout the United States and Canada. A member of the International Boxing Hall of Fame, Ratner, one of the most respected people in combat sports, is long overdue to be inducted in the UFC Hall of Fame, as well.

-- Helwani

'Big' John McCarthy has been referee for some of the most iconic fights in UFC history. Jeff Bottari/Zuffa LLC/Getty Images

15. John McCarthy, former MMA referee

The most influential MMA referee of all time, McCarthy didn't just enforce the rules of the sport, he helped write them. McCarthy was there from the very beginning, including the days when few states knew what to do with the sport or even wanted anything to do with it. McCarthy has officiated countless fights across the globe and has been at the center of some of the greatest moments in its history. "Let's get it on!"

-- Okamoto

Joe Silva was a matchmaker with the UFC from 2001 until he retired in 2016. AP Photo/Jeff Chiu

16. Joe Silva, former UFC matchmaker

Silva started working with the UFC in 1993 and retired at the end of 2016. During that time, he became instrumental in the fighters who made the UFC, who they fought, what their contracts were and when they left the promotion. UFC announcer Jon Anik aptly described Silva as "the lifeblood" of the company, wearing many different hats in addition to his matchmaker responsibilities. Seven months after retiring, Silva was honored with a spot in the UFC Hall of Fame. Name a great fight inside the Octagon, and there's a pretty good chance Silva had something to do with it.

-- Tamiso

Jeff Blatnick was a commentator with the UFC from 1994 until 2001. AP Photo/Trovati

17. Jeff Blatnick, former UFC commentator and commissioner

Blatnick, a revered Olympic gold medalist, understood the UFC's problem with sanctioning and distribution. He had served as a UFC commentator in its early days and was elevated to UFC commissioner right before the turn of the millennium. He pushed to rebrand "no-holds-barred" fighting to the far more palatable "mixed martial arts."

With his prompting -- and credibility -- New Jersey regulated mixed martial arts in 2000 and Nevada soon followed. Blatnick was among the group that helped formalize the Unified Rules, as well as formulation of rounds and judging criteria. In 2015, the UFC formally recognized Blatnick's integral role in the growth of mixed martial arts, inducting him into the contributor's wing of the UFC Hall of Fame.

-- Murphy

Randy Couture was a multiple-time UFC light heavyweight and heavyweight champion. Josh Hedges/Zuffa LLC/Getty Images

18. Randy Couture, former UFC light heavyweight and heavyweight champion

Couture was synonymous with championship fights, and the UFC record book proves it. He is the first person to win UFC belts in multiple weight classes, and he's tied for the promotional record with 15 title fight appearances (in 24 total UFC appearances).

"The Natural" was ageless. He's the first -- and only -- UFC champion over 40, and wasn't dethroned until after his 45th birthday. Daniel Cormier is the first fighter within six years of Couture's age to hold a UFC title. Couture's six title reigns are also a UFC record.

-- Murphy

Brock Lesnar defeated Randy Couture in 2008 to claim the UFC's heavyweight belt. Cooper Neill/Zuffa LLC/Getty Images

19. Brock Lesnar, former UFC heavyweight champion

He might not be everyone's cup of tea, but there's no denying Lesnar's impact on the UFC. He steamrollered Randy Couture to win the heavyweight title in 2008 with only three pro fights under his belt and instantly became one of the biggest draws in the sport's history. Yes, his UFC tenure is a complicated one -- and you can't ignore the debacle his involvement at UFC 200 turned into -- however, Lesnar will forever go down as one of the biggest draws in UFC history.

-- Helwani

Anderson Silva was UFC middleweight champion from 2006 until 2013. James Law/Zuffa LLC/Getty Images

20. Anderson Silva, former UFC middleweight champion

There was a time, not too long ago, when it seemed as if Silva would never lose. Of course, he did (a few times) and his legacy has been somewhat tarnished because of repeated PED offenses, but no one will argue the fact that Silva is one of the greatest and most dynamic fighters to compete inside the Octagon. When he was on, he was a sight to behold, and it was truly a beautiful thing to watch.

-- Helwani

Ari Emanuel was instrumental in WME-IMG purchasing the UFC in 2016 for more than $4 billion. Jerry Perez/PacificCoastNews/Newscom

T-21. Ari Emanuel, CEO, William Morris Endeavor

Emanuel is the CEO of Endeavor, which orchestrated the $4 billion purchase of the UFC in 2016. His fingerprints were on it well before then, however. Emanuel helped broker the UFC's first network television deal with Fox in 2011, and he negotiated the recent $1.5 billion deal with ESPN. His international business connections have long benefited the UFC and will continue to play a role in its expansion.

-- Okamoto

Ken Shamrock became the first UFC Superfight champion when he defeated Dan Severn at UFC 6. Troy Taormina/USA TODAY Sports

T-21. Ken Shamrock, former UFC superfight champion

Shamrock was the original pound-for-pound king, in an age when that title was far more objective. He became the first superfight champion, an open-weight class, at UFC 6 by tapping out fellow Hall of Famer Dan Severn in 2 minutes, 14 seconds.

Shamrock founded the Lion's Den, one of the most renowned mixed martial arts training centers of the pre-Zuffa era. The gym helped produce champions in three of the UFC's original four weight classes.

"The world's most dangerous man" rose to fame in Japan's Pancrase promotion in the early 1990s before entering UFC 1. He was one of the first American MMA stars, competing in every main event from UFC 5 to 9. Alongside rival Royce Gracie, Shamrock was one of two members in the UFC's first Hall of Fame class.

-- Murphy

Dana White called Stephan Bonnar vs. Forest Griffin the "most important fight in UFC history." Josh Hedges/Zuffa LLC/Getty Images

23. Stephan Bonnar and Forrest Griffin, 'The Ultimate Fighter I' finalists

It's anyone's guess where the UFC would be had these two not delivered an instant classic at the conclusion of "The Ultimate Fighter 1." The UFC was upside-down at the time in terms of how much the Fertitta brothers had invested with no return. The company was begging its way onto cable television. Griffin/Bonnar was the spark it needed in 2005, and it set off a reality TV series that still exists.

-- Okamoto

Joe Rogan has provided analysis for many of the UFC's most important fights. Jeff Bottari/Zuffa LLC/Getty Images

24. Joe Rogan, UFC commentator

It's truly hard to imagine a big UFC fight without the voice of Rogan. A former taekwondo champion who later became a black belt in Brazilian jiu-jitsu, he began as a backstage and postfight commentator for the promotion in 1997 and later became its color commentator in 2002. Rogan has provided analysis for some of the sport's most important bouts, bringing fans closer to the action while explaining some of the most technical parts of the fight. When you think UFC, you think Rogan. Plain and simple.

-- Rosenstein

Matt Hughes defended the UFC's welterweight title seven times in his career. Josh Hedges/Zuffa LLC/Getty Images

25. Matt Hughes, former UFC welterweight champion

One of the greatest champions the UFC has ever produced. He defended his welterweight title seven times, when it was considered the golden weight class in the sport. That weight class has a rich history, in large part thanks to Hughes. His Midwest country boy, wrestling mentality won over an entire generation of UFC fans, and he became an ambassador of the sport when his career ended in 2011. One of a kind.

-- Okamoto