#1 Conor McGregor vs. Jose Aldo
Then-Interim UFC Featherweight Champion Conor McGregor faced Undisputed UFC Featherweight Champion Jose Aldo at UFC 194 back in 2015. The build-up to the fight featured McGregor talking a considerable amount of trash against Aldo, whilst the latter had remained relatively stoic for the most part.
When the duo finally faced off inside the Octagon at UFC 194, it only took McGregor 13 seconds to knock the legendary Aldo out cold. While they say that hindsight is 20/20 -- in the aftermath of the fight, most experts noted that McGregor's mind-games played a huge role in his easy win against Aldo.
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After all, it was one of the rare occasions when Aldo completely abandoned his footwork, and instead, literally charged towards his foe in a straight line -- only to get countered with a huge pull-back left hand by McGregor. The latter then landed a picture-perfect hammer-fist on Aldo, who was already out before his body hit the mat.
McGregor had beaten Aldo by way of KO and was the new UFC Featherweight Champion. Needless to say, Aldo's poor choice of footwork in the aforementioned fight, has now gone down in MMA lore as one of the biggest mistakes in a UFC Championship fight.
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