



5. Jason Thacker





4. Jesse Taylor





3. James Toney





2. Renzo Gracie





1. Kazushi Sakuraba

"To say this is one and done, I think that's premature."Those were the words of CM Punk, real name Phil Brooks, ahead of his UFC--and professional mixed martial arts--debut. He will face Mickey Gall at UFC 203 on Saturday, September 10.The former WWE superstar-turned-UFC welterweight isn't the first high-profile name to join the UFC early into his MMA career. I'm looking at Brock Lesnar, but he certainly has the most questions surrounding him. Unlike Lesnar, a former NCAA wrestling champion, Punk essentially has zero athletic experience outside of the WWE heading in his UFC bout.If Gall ends up getting his hand raised, what will happen to Punk next? Will the UFC give him another chance, or will he actually become a "one and done"?If his debut is anything like these next five, we probably won't see the Chicago native take the walk to the Octagon for a second time. Without further ado, here are FloCombat's Top 5 examples of "one-and-done" fighters in UFC history.Oh, Jason Thacker…The butt of everyone's jokes during the inaugural season of The Ultimate Fighter and the most elusive man in MMA was the only member of that season with no mixed martial arts experience.Needless to say, he was a fish out of water, as he was mercilessly picked on by the other fighters. The image of Chris Leben urinating on Thacker's bed during the first night in the house has become synonymous with the long-running TV series.While he was eventually voted off the show (yes, that was a thing), Thacker would end up getting his chance at revenge, as he squared off against Leben at the TUF Finale. He lost the fight via TKO and went back into seclusion, never stepping foot in the Octagon--or any cage--againWhile his UFC career lasted a grand total of 95 seconds, it will forever be remembered as one of the most memorable, and important, in the company's history.While Jesse Taylor only had one fight in the UFC, it almost didn't happen due to a drunk rampage during his time on TUF 7.After Taylor earned his way to the final round of the show's middleweight tournament, he decided celebrate in Las Vegas after filming ending. Unfortunately, CCTV cameras were still rolling, as they caught Taylor smashing out the window of a limousine while screaming "I'm a UFC fighter" at hotel workers and guests.UFC President Dana White not only cut Taylor from the finals but also handed him his walking papers before he even made his promotional debut. But after cleaning up his act, which included attending AA classes, Taylor was given a second chance with the world's biggest fight promotion.Taylor would go on to lose to fellow TUF 7 cast member CB Dolloway by way of first-round Peruvian necktie. Taylor was then promptly released from the UFC. Since that night, Taylor has fought all over the world, earning gold for Cage Warriors, King of Champion, and Total Combat.As a former three-weight world boxing champion, while also being voted by both The Ring magazine and the Boxing Writers Association of America (BWAA) as their "Fighter of the Year" in 1991 and 2003, James Toney held some of the most impressive résumés in UFC history. So when he announced he would don the four-ounce gloves and try his hand at mixed martial arts, the fighting world eagerly took notice.Toney was eventually paired up with UFC Hall of Famer Randy Couture for his dance inside the Octagon. While he may have talked a big game, Toney's MMA skill set left much to be desired, as he was taken down just 15 seconds into the fight. After a few more minutes of toying with his squirming opponent, Couture effortlessly sunk in an arm-triangle choke, forcing the boxer to submit.And just like that, the UFC's James Toney experience was no more.A world famous Brazilian jiu-jitsu coach, Renzo Gracie has helped train a number of high-profile fighters, such as former champs Georges St-Pierre, Frankie Edgar, Chris Weidman and Matt Serra.So when the UFC announced Gracie signed a six-fight contract in 2009 and was set face former UFC welterweight champ Matt Hughes at UFC 112 in Abu Dhabi, the hype around the fight became palpable.Entering the bout, Gracie hadn't fought since his second-round win over former UFC light heavyweight champ Frank Shamrock. This marked his third-straight win over a former UFC champ after coming out on top over Carlos Newton and Pat Miletich as well.While the Brazilian initially held his own against Hughes, the barrage of leg kicks eventually took their toll. By the third round, Hughes had taken full control of the fight with his stand-up attack, unloading a series of uppercuts and hooks to the skull of Gracie. The referee would eventually save Gracie from further damage late in the third round.Gracie hasn't been seen inside a ring or a cage since.I know what you're thinking. Yes, technically Sakuraba had two fights inside the UFC Octagon, but since both happened on the same night against the same person and this is my list, he takes the top spot in the 'one and done' category.The Japanese icon entered the UFC's one night, four-man tournament in 1997 as a late-hour replacement for the injured Hiromitsu Kanehara. Weighing 183 pounds, almost 20 pounds under the UFC's 200-pound requirement, Sakuraba faced the 60-pounds-heavier Marcus "Conan" Silveira in the opening round. After John McCarthy prematurely stopped the fight, mistaking a Sakuraba takedown for a fight-finishing punch, Sakuraba iconically refused to leave the cage until all was righted.But then, in what can only be described as divine intervention, fellow fighter Tank Abbott broke his hand in his opening-round win, forcing him out of the tournament. Then the alternate fighter, Tra Telligman, revealed he too was injured. So the decision was made to allow Sakuraba back in to rematch Silveira in the tournament's championship match. Sakuraba would go on to submit his hulking opponent.The rest, as they say, is history. Sakuraba would go on to become arguably the most famous Japanese fighter in combat sports history, as he picked up wins over former UFC champions Newton, Vitor Belfort, Quinton Jackson, Kevin Randleman and three-time UFC Tournament champion Royce Gracie.