Conor McGregor and 4 other UFC champions who beat their division's GOAT but never successfully defended their title with a win
The goal of nearly every UFC fighter is to capture an undisputed championship belt in the promotion. On certain occasions, the reigning champions with whom a top contender must fight are all-time greats, and in some cases, they are the greatest fighters in their division's history.
Thus, beating them proves a tall task for even their greatest contemporaries, which leads to the notion that they're unbeatable, as they reign over their division without equal. In time, however, a challenger rises to the occasion and finally dethrones them as champions to herald a new era.
Unfortunately, not every new champion who dethrones their division's GOAT is destined for a long tenure as the new titleholder. In fact, some newly minted champions never successfully defend their title, even after decisively beating their divisional GOAT.
#5. Alexa Grasso, current UFC women's flyweight champion
Alexa Grasso is in an odd position as the women's flyweight champion. She captured the title in a shocking win over Valentina Shevchenko, the 125-pound GOAT. In submitting her in round four at UFC 285, she authored one of the greatest upsets of 2023.
However, their subsequent bout, an immediate title rematch, had a widely criticized outcome. Grasso held the advantage on the feet with her crisp boxing and sharp hands, while Shevchenko's physicality and superior wrestling enabled her to score takedowns in a competitive fight that many felt she had done enough to win.
Instead, the judges ruled their bout a draw, so while Grasso retained her championship strap, she didn't actually defend it and is still searching for her first successful 125-pound title defense.
#4. Julianna Peña, former UFC women's bantamweight champion
Toward the end of 2021, Julianna Peña took on the then insurmountable task of facing Amanda Nunes for the women's bantamweight title. 'The Lioness' is hailed as the greatest female fighter of all time, and with good reason, given her number of title defenses and how many champions and all-time greats she's beaten.
Yet, at UFC 269, Peña did the impossible. She neutralized her foe's ability to build combinations off her jab by jabbing with her, causing Nunes to tire quickly. Within two rounds, 'The Venezuelan Vixen' emerged victorious, submitting Nunes with a rear-naked choke to dethrone her at 135 pounds.
Unfortunately for her, their immediate rematch at UFC 277 was a dominant win in Nunes' favor, as the legendary Brazilian scored multiple knockdowns to reclaim her title, leaving Peña with no successful title defenses.
#3. Cody Garbrandt, former UFC bantamweight champion
There was a time when Cody Garbrandt was an undefeated force and one of the hottest knockout artists on the entire roster. With a perfect 10-0 record, he challenged the then reigning bantamweight champion, Dominick Cruz, whose number of victories over Team Alpha Male, the latter's gym, was embarrassing.
Cruz was, and still is, regarded as the greatest bantamweight of all time, with only Aljamain Sterling, whose tenure as the 135-pound champion was questionable, being comparable. Given Garbrandt's hotheaded nature and Cruz seeming unbeatable at the time, no one thought him capable of winning.
Check out T.J. Dillashaw TKO'ing Cody Garbrandt:
But at UFC 207, Garbrandt was the star of one of the greatest title-winning performances in the promotion's history, outstriking Cruz with supreme ease. What was assumed to be the start of the Garbrandt era, however, was instead the start of a downward spiral as he immediately lost his title to T.J. Dillashaw.
#2. Matt Serra, former UFC welterweight champion
Ahead of his UFC 69 bout with the great Georges St-Pierre, Matt Serra was a historic underdog. Hardly anyone gave him a chance to win, but who could have foreseen the events that followed besides Serra himself? He faced the Canadian in front of 15,000 Texans and never allowed the occasion to get to him.
Instead, he annihilated 'GSP' within three minutes, TKO'ing him in arguably the greatest upset in MMA history to become the welterweight champion. While his win drew tremendous attention, Serra was subsequently faced with the daunting task of defending his title against St-Pierre in a rematch.
This, however, ended in failure, as he was unsuccessful, dropping the title to 'GSP' in an immediate rematch. Afterward, Serra never again fought for a title and retired within two years.
#1. Conor McGregor, former UFC featherweight/lightweight champion
Conor McGregor's featherweight campaign has become the stuff of legend. However, none of the Irishman's stardom would have been possible had he not beaten the then reigning featherweight champion, José Aldo, who is still widely regarded as the greatest 145-pounder of all time.
The pair crossed swords at UFC 194, and McGregor needed just 13 seconds to knock the legendary Brazilain out cold. It was and remains the fastest knockout in UFC title history, but McGregor never stepped on the scale at 145 pounds ever again, as he pursued the lightweight title after that.
After a long spell of inactivity in the division, McGregor was stripped of his featherweight title without ever mounting a single title defense.