Fighting in the UFC is considered by many MMA fighters to be the pinnacle achievement in one's sporting career. Its rankings are populated by elite athletes only, so the UFC's viewers are often treated to some of the greatest contests in all of combat sports.Occasionally fighters compete against each other before they have truly hit their prime, or a fight can be so close that even the judges are split. Whilst the UFC occasionally books rematches, more often than not, the rankings and unpredictable nature of MMA ensure the winner progresses whilst the loser drops down.In this list, we will be going over five fights that could make up the main card of a 'rematches only' event. To be eligible for the event, the fighters must currently be competing for the UFC, which rules out the likes of Khabib Nurmagomedov, Daniel Cormier or Georges St-Pierre. We will also not be considering trilogy fights or rematches that have already been booked.Honorable mentions that could arguably be placed on the prelims of such an event go to Chan Sung Jung vs. Yair Rodriguez, Stephen Thompson vs. Jorge Masvidal and Josh Emmet vs. Shane Burgos.#5. Zhang Weili vs. Joanna Jedrzejczyk 2 - UFC strawweightOne of the most entertaining fights to have taken place in the UFC over the past five years regardless of weight class was the strawweight title fight between Joanna Jedrzejczyk and Zhang Weili.UFC 248 Adesanya v RomeroIt is a fight now considered by many to be the greatest fight in the history of women's MMA. Both Jedrzejczyk and Weili fought their absolute hearts out, leaving nothing behind in the octagon.Rewatch the fight that had everybody screaming "OH!" 😮Zhang Weili vs. Joanna Jedrzejczyk kicks off #UFCNight tonight on ESPN pic.twitter.com/9q1evgzGN0— ESPN MMA (@espnmma) March 28, 2020Weli ultimately won via the judges' decision. However, it truly could have gone either way. Weli Zhang has since lost her strawweight belt to Rose Namajunas, whilst Jedrzejczyk has not fought since. A rematch between the two elite strawweights would be the perfect opening fight for the main card of a 'rematches only' UFC event.Just look at the reaction from the fighters following the end of Zhang Weili vs. Joanna Jędrzejczyk. Standing O. If that isn't the fight of the year then we're in for an incredible 2020.pic.twitter.com/y1XtQcTIUy— Chamatkar Sandhu (@SandhuMMA) March 8, 2020