#2. Georges St-Pierre vs. Johny Hendricks (UFC 167)

By the time he fought Johny Hendricks at UFC 167, Georges St-Pierre had established himself as one of the greatest fighters in UFC history. ‘Rush’ had held the UFC welterweight title since 2008, and had defended it a record eight times.
But while he’d dominated the likes of Carlos Condit, Josh Koscheck and Nick Diaz, GSP simply couldn’t do the same to Hendricks. ‘Bigg Rigg’ hurt him with strikes, became one of the few fighters to take him down, and when the fight ended, it looked like St-Pierre’s title reign was over.
Get the latest updates on One Championship Rankings at Sportskeeda and more
However, the judges saw things the other way, handing St-Pierre a razor-close decision victory. Even big fans of the Canadian believed that he’d probably gotten away with one, and fully expected the UFC to book an immediate rematch.
But despite UFC president Dana White claiming that St-Pierre “owed” everyone – from the UFC and the fans to Hendricks – the rematch, the Canadian was having none of it, and instead took an indefinite leave of absence from the UFC.
His UFC welterweight title was vacated, and although Hendricks would claim it by beating Robbie Lawler, he never did get his rematch with GSP, who would return at UFC 217 nearly four years later, coincidentally at the same event that saw ‘Bigg Rigg’ fight for the final time in the UFC.
And in turn, this meant that UFC fans were deprived of finding out whether Hendricks really was the man who could’ve dethroned GSP in his prime.
#1. Khabib Nurmagomedov vs. Conor McGregor (UFC 229)

Unlike most of the fights on this list, the clash between Khabib Nurmagomedov and Conor McGregor was not a close fight by any means. Instead, Nurmagomedov largely dominated ‘The Notorious’ Irishman en route to a crushing fourth-round submission win. However, that didn’t mean that UFC fans around the world weren’t clamoring for a rematch between the two.
Major fans of McGregor were obviously desperate to see it to find out if their favorite would be able to garner any kind of revenge over his nemesis, while fans of Khabib, and those who didn’t like McGregor, simply wanted to see the Irishman take another beating.
The UFC, meanwhile, seemed equally happy to push the idea of a potential Khabib vs. McGregor rematch – an understandable sentiment given that the fight pulled in a UFC record of over two million pay-per-view buys.
However, the one man who didn’t seem at all interested in a rematch was Nurmagomedov. Despite continually slinging insults at McGregor over social media, ‘The Eagle’ always maintained he didn’t want to fight the former two-division champ again.
Essentially, he felt that he had nothing to prove, and didn’t really want to give the Irishman any more of a platform to display his disrespect.
So rather than face McGregor in a mega-money rematch, Khabib instead defeated Dustin Poirier and Justin Gaethje before deciding to step away from the UFC for good, fulfilling a promise made to his mother.
And despite the two rivals still sniping at one another on social media, three years down the line from their first meeting, it now seems that any hope of a Nurmagomedov/McGregor rematch is long gone.