As mixed martial arts has evolved, it has endured both its ups and downs over the course of its history, which is nearing the 20-year mark.
Now, with the sport inching closer to the mainstream, every aspect will be scrutinized to the finest detail.
Even so, it has already survived a number of controversial and surprising events that could have easily derailed its growth. Promotions have come and gone and fighters have made poor choices, but in the end, the sport is bigger than ever.
Let's take a look back at some of these events over the last five years.
Photo: Seth Petruzelli celebrates his win over Kimbo Slice - Sherdog
In early 2007, the MMA world was shocked as UFC-parent company Zuffa acquired their biggest rival, Pride Fighting Championships.
The Las Vegas-based company reportedly paid $70 million for the Japanese-owned promotion. However, it was unaware of the existing debt the promotion possessed. Initially, it was expected that Zuffa would keep Pride alive and run events in parallel with the UFC, but due to the debt concerns and a messy legal situation with the former owners, the promotion was laid to rest.
As a result, Pride superstars such as Wanderlei Silva, Mauricio "Shogun" Rua, and Mirko "Cro Cop" Filipović were shifted to the UFC. Many diehard fans of the promotion were outraged, and although Zuffa has begun to use footage and logos of Pride, there are no immediate plans to resurrect the promotion.
In early June of 2007, a long-awaited rematch between UFC legend Royce Gracie and his family's nemesis "The Gracie Hunter" Kazushi Sakuraba took place under the EliteXC banner. Gracie would take home a unanimous decision in a fight that failed to live up to its expectations.
Following the bout, the California State Athletic Commission revealed that Gracie had tested positive for extremely high levels of the steroid Nandrolone. Gracie disputed the test results, but ultimately was fined $2,500 and was suspended for the remainder of his license.
While the positive test does not change what the Hall of Famer did for the sport, Gracie has not fought since.
Light heavyweight Quinton "Rampage" Jackson captured UFC gold not long after moving over from the Pride organization. However, his title run did not last long as he was defeated by Ultimate Fighter winner Forrest Griffin at UFC 86. The closely-contested bout saw all three judges award Griffin the decision and the UFC title.
In the days after the bout, Jackson, still upset about the fights result, revealed how he earned his moniker by terrorizing the suburbs of Costa Mesa, California.
The fighter drove his Ford pickup with a flat tire while talking on his cell phone, and failed to pull over when police tried to stop him. As a result, Jackson earned charges of felony evading, reckless driving and hit-and-run.
Luckily for Jackson, he would avoid jail time and later apologized for the "Rampage."
In a sad turn of events, former UFC middleweight champion Evan Tanner died alone in the Southern California desert in late 2008. The fighter had overcome a two-year absence from the sport in which he battled alcohol problems. However, he lost both bouts after his return.
Many had speculated that Tanner's adventurous side would ultimately lead to his death and unfortunately, they were right.
The former champion elected to go camping alone to ride his dirt bike and assured everyone that the trip was nothing out of the ordinary. Tanner would run out of gas and attempted to walk back to camp in temperatures as high as 118 degrees.
His friends reported him missing five days prior to the discovery of his body.
The rise and fall of EliteXC can largely be tied to the career of one fighter, Kevin "Kimbo Slice" Ferguson. The YouTube sensation helped the promotion quickly establish a following and helped them secure a network television deal.
Unfortunately, Ferguson was far from an accomplished mixed martial artist. When his scheduled opponent, Ken Shamrock, was injured during pre-fight warm-ups, Ultimate Fighter cast-off Seth Petruzelli stepped in to face Ferguson.
It took only 14 seconds for Petruzelli to overwhelm Ferguson, exposing him and setting up the end of the promotion. While Gus Johnson's over-dramatic assessment of the upset may have been too much, it was a fitting end to that chapter in MMA history.
As if that wasn't bad enough that heavyweight Josh Barnett was famously stripped of the UFC title due to a positive steroids test in 2002, the fighter would again test positive and single-handedly put an end to the Affliction promotion.
Barnett was scheduled to face MMA legend Fedor Emelianenko at the promotion's third event, but tested positive for a metabolite of Drostanolone in his pre-fight test. The California State Athletic Commission denied his license just 10 days before the scheduled bout.
With no opponent for the Russian, Affliction scrapped the event altogether and eventually folded. Barnett would continue his professional wrestling career in Japan and eventually would go on to sign with Strikeforce.
As Strikeforce continued its growth, it also secured a network TV deal and worked to build both its brand and its fighters. However, the promotion's visit to Nashville, Tenn., was anything but what was expected.
With three title fights being showcased on the CBS broadcast, few thought all three fights would see the judges' scorecards, but that's exactly what happened and the broadcast ran long. As if that wasn't enough, a messy brawl would take place following the Jake Shields versus Dan Henderson main event.
As Shields celebrated with his teammates, Gilbert Melendez and Nick and Nate Diaz, the always outspoken Jason "Mayhem" Miller made his way inside the cage. Shields and his teammates were less than pleased with Miller's actions and all hell broke loose live on CBS.
Once again, Gus Johnson was there to inaccurately assess the situation and the promotion has not been broadcast on network television since.
After an onslaught of pre-fight trash talk between welterweights Paul Daley and Josh Koscheck, many expected fireworks inside the Octagon at UFC 113.
However, the former national champion wrestler, Koscheck, utilized his grappling prowess perfectly to neutralize the dangerous British striker, Daley.
Unable to mount offense during the fight from his back, Daley waited until after the final bell to score the most significant strike of the bout. As Koscheck celebrated his dominant performance, Daley connected with an uppercut on his unsuspecting opponent. Referee Dan Miragliotta quickly stepped in and stopped the attack.
Immediately after the fight, UFC President Dana White released Daley from the promotion for his actions.
No fighter in MMA is unbeatable. That fact was driven home by Brazilian heavyweight Fabrico Werdum when he submitted MMA legend Fedor Emelianenko under the Strikeforce banner.
Emelianenko was long touted as the greatest fighter to walk the planet, suffering only one, controversial defeat prior to the fight with Werdum. However, that came crashing down when he fell victim to a triangle-armbar in only a minute.
Werdum is one of the most dangerous Brazilian Jiu-Jitsu practitioners in MMA and capitalized on the Russian's overconfidence to score the dramatic upset. Following that fight, Emelianenko would drop two more fights and would be cut by the promotion.
Multiple-time boxing champion James "Lights Out" Toney proved that persistence can pay off as he relentlessly hounded UFC President Dana White about competing in the Octagon.
Unfortunately for Toney, his ability to compete as a mixed martial artist fell short of his ability to run his mouth. The former IBF champion was given a co-main event fight with UFC Hall of Famer and multiple-time UFC champion Randy Couture at UFC 118.
Couture only needed seconds to bring the fight to the ground with a low, single leg takedown. Once on the ground, Toney was a fish out of water. Once Couture moved to the mount, it was only a matter of time before the end would come. An arm-triangle choke forced Toney to submit and spelled the end of his career in the UFC.
Although most fans remember the UFC 117 main event as a dominant performance by contender Chael Sonnen before he was submitted by champion Anderson Silva in the fifth and final round, most have forgotten that Sonnen failed his post-fight drug test.
Following the bout, in which Sonnen used his wrestling to control the Brazilian, Sonnen's levels of testosterone were off the charts. Had he been victorious, the California State Athletic Commission would have not only fined and suspended Sonnen, they would have stripped him of the UFC middleweight championship and the fight would've been declared a no contest.
Sonnen has blamed his doctors for the test result, citing that he suffers from hypogonadism. Regardless, he served his suspension and was out of action for an entire year. He is now slated to rematch Silva at UFC 147.
In a surprise move, UFC-parent company Zuffa purchased their biggest competitor, Strikeforce, in early 2011. Although the San Jose-based company had been public about finding investors, it was not anticipated that Zuffa would make a run at the promotion.
As part of the deal, Strikeforce founder and CEO Scott Coker remained in place but the majority of the company's employees were let go and their roles were taken over by existing Zuffa employees.
Additionally, the promotion's broadcast deal with Showtime remained in place, ensuring, for the time being, that the promotion would continue to operate. The Showtime contract was renewed in early 2012 and six events are planned for the coming year.
In only a matter of hours, former middleweight title challenger Nate Marquardt went from headlining the UFC's fourth event on Versus to being unemployed. The veteran was expected to make his welterweight debut against Rick Story at the event but failed to receive medical clearance from the Pennsylvania State Athletic Commission.
As it turns out, Marquardt had been receiving treatment for low levels of testosterone for the previous eight months. However, following his UFC 128 victory over Dan Miller, he was asked to stop the treatment and undergo a series of tests by the New Jersey State Athletic Commission. When he resumed treatment, the fighter was unable to get his testosterone levels under control and was not allowed to fight.
UFC President Dana White reacted quickly and harshly, releasing Marquardt from the promotion immediately. The fighter briefly signed with the BAMMA promotion, but did not compete under their banner. Marquardt recently signed with UFC sister promotion Strikeforce.
In martial arts each discipline has its own unique set of equipment and clothing. As these disciplines have transitioned to the sport of MMA, their practitioners have carried over some of these practices into the Octagon. However, the majority of fighters have opted to wear MMA-specific board shorts for competition.
At UFC 133, longtime veteran Dennis Hallman took cage attire to a level not seen in quite some time. For his bout with Brian Ebersole, Hallman entered the cage wearing a blue Speedo. His wardrobe drew both laughter and dismay from the Philadelphia crowd and pay-per-view audience.
Hallman would lose the bout by TKO and Dana White awarded Ebersole an "of the night" bonus for quickly removing Hallman from view. Although Hallman was not the first fighter to step into the cage with questionable attire, White quickly proclaimed that Speedos were now banned from the UFC.
Just when Brazilian powerhouse Cristiane "Cyborg" Santos returned from a lengthy absence to dismantle her most recent opponent and defend her Strikeforce championship, the fighter tested positive for the drug Stanozolol.
As a result, she was stripped of her title and suspended for a year. Additionally, her win over Hiroko Yamanaka was changed to a no contest.
Santos plans to appeal the test results, but the future of Strikeforce's 145-pound division is now gloomy at best.