#2 Conor McGregor vs Khabib Nurmagomedov

Conor McGregor faced his biggest rival and reigning UFC lightweight champion at the time, Khabib Nurmagomedov, at UFC 229. There was a lot of bad blood between the two fighters, with 'The Eagle' even threatening to hospitalize 'The Notorious' in case of an encounter outside the UFC.
At UFC 229, Khabib Nurmagomedov mauled Conor McGregor for four rounds before submitting him via neck crank. It was one of the most humiliating losses of his career for the former UFC double champion. Five months later, McGregor announced his retirement, causing fans to give up on him and believing that he was done for good.
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However, following his usual pattern, Conor McGregor came out of retirement with a bang. He first got into a little beef with UFC president Dana White and then entered the octagon at UFC 246 to face Donald Cerrone. Announcing his return and proving his doubters wrong, 'The Notorious' knocked out 'Cowboy' in 40 seconds in dominating fashion.
Also Read: Conor McGregor medically suspended from competing in the UFC until 2022.
#1 Conor McGregor's UFC 264 loss and injury

Conor McGregor's latest setback came at UFC 264. Coming in for the trilogy bout against Dustin Poirier, McGregor was fired up and as mean as ever. He engaged in a lot of trash talk against 'The Diamond' and promised to 'absolutely destroy' him during the fight.
While McGregor made a fiery entry at UFC 264 by landing a barrage of kicks on Dustin Poirier, he soon ended up on the floor following a takedown. Following a little ground and pound by Poirier, the two fighters got back on their feet in the last minute of the first round.
Conor McGregor, who had compromised his shin earlier in the fight, suffered a freak injury in the dying seconds of round one. With the fight ending in a TKO win for Dustin Poirier via doctor's stoppage, McGregor was stretchered out of the arena.
'The Notorious' stands doubted yet again by UFC fans, who suspect whether the superstar will be able to return from this setback.
Apart from the lengthy medical suspension that Conor McGregor faces for recovery, his injury could also see the UFC star's prime slip away for good. Many UFC fans, analysts and fighters have already written him off.
Can Conor McGregor prove his doubters wrong this time around? Let us know in the comments.