Super-fights are hard to make. Just ask UFC president Dana White whose unfortunately failed to book some blockbuster clashes inside the famed Octagon.
Who doesn't love a super-fight?! A dream battle of champion vs. champion or superstar vs. superstar not only generates massive numbers but also satisfies fans' craving for huge match-ups.
We've had the likes of Chuck Liddell vs. Wanderlei Silva and Georges St-Pierre vs. BJ Penn, but we've also missed out on a few gigantic fights.
SPORTbible looks at four of the biggest UFC super-fights that fans have missed out on over the years.
4. Randy Couture vs. Fedor Emelianenko
The original super-fight that never happened. It was talked about for a long time and is still talked about today.
A heavyweight clash between two all-time greats was teased in 2008, and nearly happened away from the UFC who ultimately prevented it from happening.
So, basically, Couture and the UFC were embroiled in an ugly legal dispute with the ex-UFC light-heavyweight and heavyweight champion rebelling against the promotion.
He showed up at a rival's show in the form of Affliction and turned up on their broadcast and even faced off with the Russian legend following his victory over Tim Sylvia.
But Couture failed to escape UFC's shackles and he was unable to get his hands on 'The Last Emperor' to the disappointment of the MMA community.
3. Cyborg vs. Ronda Rousey
It never happened, but Rousey and Cyborg talked about a potential showdown to the point where the rivalry became one of the most intense in UFC history.
They never got to settle their differences inside the cage after failing to overcome the biggest hurdle the super-fight faced; weight.
Rousey campaigned in the bantamweight division while Cyborg enjoyed most of her career at featherweight.
While there were talks of meeting at a catchweight, Rousey refused to gain any extra weight and insisted that if the Brazilian can fight at 145lb using steroids - which she tested positive for in 2011 - then she should have no problem getting to her weight.
Rousey vs. Cyborg ended up as another disappointing UFC fantasy.
2. Brock Lesnar vs. Fedor Emelianenko
They say everything's bigger in Texas and the Lone Star State almost landed one of the biggest fights in UFC history.
White has called Lesnar vs. Emelianenko his biggest match-making regret after failing to book the mega clash.
Lesnar boxed off four straight UFC victories after losing his promotional debut to Frank Mir. He outpointed Heath Herring before claiming the UFC heavyweight title against Couture in a one-sided demolition then successfully defend his belt against Mir and Shane Carwin. He was the scariest fighter in the sport. A disturbing combination of raw athletic ability and incredible strength.
Meanwhile, Emelianenko was wreaking havoc in Japan before moving to America where he took out a couple of former UFC champions in Sylvia and Andrei Arlovski. His work wasn't going unnoticed as White looked into the booking him against his champion at Cowboys Stadium.
Talks progressed well and it was so, so close from becoming a reality until the tragic passing of Emelianenko's father. The untimely death nixed any plan of Emelianenko facing Lesnar.
1. Anderson Silva vs. Georges St-Pierre
A pair of dominate champions. The consensus No.1 and No.2 pound-for-pound best fighters on the planet. It was the super-fight to end all super-fights.
Silva and GSP were not only considered elite but two individuals who changed the course of the fight game forever and left their mark on the sport.
Everyone looked hapless when they fought 'The Spider'. He'd innovate new attacks and delivered punishing beatdowns, even at the weight above.
'Rush', on the other hand, was making light work of his competition and a battle between the two kings appeared to be destined.
But weight, timing and drug testing issues sadly got in the way of UFC's equivalent to Floyd Mayweather vs. Manny Pacquiao.
The top two pound-for-pound UFC fighters in their prime trading leather would have been one hell of an event.
Topics: Anderson Silva, UFC News, MMA News, Fight News, UFC, Ronda Rousey, MMA, Brock Lesnar, Georges St-Pierre