5 most iconic title unification fights in UFC history

Every so often, UFC champions cannot defend their title for any number of reasons, be it injuries, contract negotiations, or fights in different weight classes. In such circumstances, interim champions are crowned, setting up massive title unification bouts down the line.

At the recently concluded UFC 290 pay-per-view, Alexander Volkanovski unified the featherweight belts with a dominant showing against interim champion Yair Rodriguez, further adding to his legacy.

The king of the featherweight division 👑 #UFC290 https://t.co/1otdZA1fVN

Champion vs. Champion fights are always exciting. With undisputed gold on the line, we've witnessed many historic and memorable title unification bouts, and we thought we'd rank the best of them.

On that note, here are the five most iconic title unification bouts in UFC history.

#5. Brock Lesnar vs. Shane Carwin – UFC 116

Brock Lesnar fought in two momentous title unification bouts in his MMA career. While the first of these was his iconic rematch with Frank Mir (more on that later), his subsequent title defense against Shane Carwin remains one of the greatest moments in Lesnar's career.

Going into 2010, Shane Carwin's record stood at 11-0, with 11 finishes. He advanced his record to 12-0 with his spectacular knockout win over Frank Mir for the interim title, setting up a massive clash against then-champion Brock Lesnar.

With his perfect record and 100% finish rate, Carwin was seen as a huge threat to Lesnar, who was a superstar at the time. In the very first round, 'The Beast Incarnate' was dropped and somehow made it through the opening five minutes.

After weathering the storm, Lesnar mustered one of the greatest comebacks in UFC history by turning the tables on Carwin, submitting the interim champion in the second round. This remains the last win of Lesnar's short but eventful MMA career.

On this day in 2010, Brock Lesnar rallied to submit Shane Carwin at UFC 116 🔥 #UFC116 #MMA https://t.co/xrhJF0mKpw

#4. Robert Whittaker vs Israel Adesanya 1 – UFC 243

Coming off his two barnburners with Yoel Romero, Robert Whittaker was seen as one of the best fighters on the roster. 'The Reaper's unbeaten run at middleweight saw him run through contenders en route to the title, but health complications forced him to remain on the sidelines in 2019.

As such, Israel Adesanya and Kelvin Gastelum collided for the interim title, with 'The Last Stylebender' emerging victorious. With two Oceanic stars now champions in the same division, Adesanya took on Whittaker in Melbourne, Australia, with a record crowd in attendance.

Israel Adesanya just changed the walkout game 🤯

@stylebender #UFC243 https://t.co/fyj6zHuqCd

UFC 243 went down at the Marvel Stadium in Melbourne and was attended by north of 57,000 people, a record that still stands today. Israel Adesanya was unbeaten then, but the Kiwi kickboxer's somewhat one-dimensional game saw the more well-rounded Robert Whittaker open as a slight favorite.

The opening round was fairly close, with both fighters getting a feel for each other's range and movement. In the dying seconds of the round, Adesanya stunned Whittaker with a crisp counter, and the champion was clearly saved by the bell.

'The Last Stylebender' stunned Whittaker again in the second round and finished the job to win undisputed gold, kicking off a historic title reign.

Undefeated. Undisputed. 🏆

@stylebender #UFC243 https://t.co/kirjD28CJq

#3. Georges St-Pierre vs. Matt Serra 2 – UFC 83

In Georges St-Pierre's second UFC run, he reeled off five wins on the trot, culminating in his title-winning performance against former champion Matt Hughes. In his first championship defense, the Canadian icon took on TUF winner Matt Serra, who delivered one of the biggest upsets in MMA history.

On this day in 2007, Matt Serra shocked the world when he TKO’d Georges St-Pierre to become the new UFC welterweight champion in Houston 🔥 #UFC69 #MMA

https://t.co/bIpSFoKzzN

Following his shocking loss to Matt Serra, Georges St-Pierre bounced back with a win over Josh Koscheck and subsequently took on former foe Matt Hughes in a trilogy bout with the interim title up for grabs.

St-Pierre closed out his rivalry with Hughes via a submission victory, setting up a rematch with Serra at UFC 83 in Montreal, Canada. 'Rush' left no doubt this time around, dominating Serra from pillar to post en route to a comfortable TKO victory in front of his compatriots.

This win kickstarted St-Pierre's legendary welterweight title reign as he stayed atop the division from 2008 till 2013 when he vacated the belt after his ninth title defense.

#UnDiaComoHoy hace 1️⃣5️⃣ años, Georges St-Pierre 🇨🇦 se tomaba la revancha noqueando 💣💥 a Matt Serra 🇺🇸 en #UFC83 y recuperando así el Título UFC 🏆 del peso wélter

🎥 @UFCEspanol

#ESPNKnockOut https://t.co/Z0ec2rlYan

#2. Brock Lesnar vs. Frank Mir 2 – UFC 100

Brock Lesnar famously lost his first-ever fight in the UFC. back in 2008, Lesnar made his octagon debut against Frank Mir, who submitted him with a kneebar just 90 seconds into their bout. Lesnar returned with a vengeance in their rematch, brutally finishing Mir to defend his heavyweight title.

Brock Lesnar vs. Frank Mir fights were WILD 😳🔥

(via @espnmma) https://t.co/cHjaBOVR8M

After his submission win over Brock Lesnar in 2008, Frank Mir took on Antônio Rodrigo Nogueira for the interim strap. By this point, Lesnar racked up two wins in the UFC, beating Heath Herring and then Randy Couture to claim the heavyweight championship.

Lesnar and Mir ran it back at UFC 100, where 'The Beast Incarnate' absolutely battered his former foe on the ground to unify the titles. Lesnar's sweet revenge remains one of the greatest moments in the history of the heavyweight division.

"And hell, I might even....." you all know the rest. #UFC100

@BrockLesnar checks in with the #1 best Octagon interview of all-time! https://t.co/dW3umoY4gM

#1. Jose Aldo vs. Conor McGregor – UFC 194

Conor McGregor's scorching rise up the featherweight division is the stuff of legend, culminating in incredible fashion in arguably the biggest title unification fight in MMA history.

Conor McGregor was on a different level when it came to trash talk 😭 https://t.co/1Y1qmSmQuQ

Conor McGregor's stardom compounded with every passing fight during his ascent up the featherweight ranks. The polarizing Irishman defeated Chad Mendes in emphatic fashion to win the interim title, setting up a historic bout with Jose Aldo, the consensus greatest 145-pounder of all time.

McGregor undoubtedly got into Aldo's head in the lead-up to the fight, constantly annoying and belittling the Brazilian icon throughout their pre-fight press tour. An unnaturally tense aura surrounded their title unification bout, which went down in Las Vegas, Nevada.

Many expected this fight to be a war, with both McGregor and Aldo being seasoned strikers. Aldo was riding a mind-blowing 18-fight win streak, but the magnitude of this grudge match against 'The Notorious' was unlike anything he, or anybody, had ever seen.

Ultimately, it was McGregor's night, as he knocked out Aldo just 13 seconds into the fight, turning the combat sports world on its head.

"OOOOOH... Unbelievable"

Step into the booth for @JoeRogan's reaction to McGregor-Aldo. #UFC229 https://t.co/j3kw2vY9uW