MMA is notoriously no country for old men (unless your name is Randy Couture), the old are fed to the young and no sport captures the sunrise and sunset of an athlete’s career quite like it.
Despite MMA having a relatively quick rise to mainstream popularity, not having the many decades of history that sports like boxing, basketball and football boast, the sport has already gone through enough generations of fighters to pinpoint certain fights in history as significant landmark matchups where fans were seeing one beloved veteran lose their spotlight to a younger opponent.
Honourable Mention: Wanderlei Silva vs Kazushi Sakuraba 2 – Pride 17

While this list is going to focus specifically on bouts that took place within the UFC, I couldn’t justify completely excluding one of the most significant bouts to take place under the company that dominated MMA in the early 2000s before the UFC truly rose to prominence, Pride Fighting Championships.
Kazushi Sakuraba is undoubtedly the most beloved icon in Japanese MMA history, he solidified his legacy by becoming known as the legendary ‘Gracie Killer’, being given this moniker as Sakuraba would go on an incredible run in 1999 and 2000, defeating four members of the legendary Gracie family, known for popularising and dominating with Brazilian Jiu-Jitsu in MMA.
This run would include a legendary battle with arguably the most famous member of the family, Royce Gracie in the 2000 Openweight Grand Prix Quarterfinals, a fight that would last an astonishing 90 minutes, before Royce’s corner would throw in the towel as Gracie couldn’t stand to answer the bell for the fourth overtime round due to accumulated damage done to his leg by Sakuraba.
After defeating Ryan Gracie at Pride 12, Sakuraba was matched up against ‘The Axe-Murderer’ Wanderlei Silva at Pride 13, where Silva would TKO the Japanese legend. After both men would win their next respective fights, the rematch was set for Pride 17, except this bout would be contested for the inaugural Pride Middleweight Championship.
While the fight may not have had the most satisfying conclusion for those in attendance at the Tokyo Dome, with Silva being awarded a TKO victory after a doctor’s stoppage due to Sakuraba suffering a broken collarbone after a slam by Wanderlei, what ‘The Axe-Murderer’ would go on to achieve in Pride was nothing short of incredible, eventually boasting the most wins, KOs, title defences and the longest winning streak in Pride history, as well as winning the 2003 Pride Middleweight Grand Prix Tournament.
While Sakuraba remained a popular figure despite the losses to Silva, it was clear that Pride had a new Middleweight kingpin coming out of Pride 17 and his name was Wanderlei Silva.
#5. Conor McGregor vs José Aldo – UFC 194

While some may argue with this particular inclusion on the list as McGregor never actually defended the Featherweight championship that he took from ‘The King of Rio’, it cannot be disputed that this fight, and the build-up beforehand was one of the most meteoric rises to prominence in any sport.
In 2015, McGregor was a new breed of trash-talker in the UFC, not since Chael Sonnen’s repeated verbal assaults on Middleweight champion Anderson Silva had the UFC faithful seen such lop-sided pre-fight exchanges on the microphone. Before the days of Gucci mink coats, Proper Twelve whiskey and boxing super-fights, there was a ‘Notorious One’ that was driven, focussed and knew all the right buttons to push to agitate his long-reigning opponent.
In addition, the match-up between the two men was originally scheduled for UFC 189, before Aldo would be forced out with an injury, leaving McGregor to face a tough opponent in Chad Mendes for the interim title. McGregor would persevere and put even more pressure on Aldo.
With a second round of media obligations to fulfil and therefore, a second round of insults by the Irishmen, it was understandable that Aldo could not wait to get his hands on McGregor. This overzealousness would cost him, as Conor would famously find a stiff left hook 13 seconds into the fight to seal the win and the championship.
Again, Conor may not have gone on to dominate the Featherweight division in the same way that Aldo did as champion and he will likely never fight at 145 pounds again, but it is tough to argue against the coronation of a figure in mixed martial arts that can still grab people’s attention and divide passionate opinions the way McGregor can half a decade on from this fight.
#4. Jon Jones vs Maurício ‘Shogun’ Rua – UFC 128

‘Shogun’ Rua was one of the last stars to emerge from PRIDE before it was bought by then-UFC parent company Zuffa in 2007. Rua would jump over to the UFC after PRIDE’s collapse with a 16-2 record, boasting victories over future UFC champions such as Quinton ‘Rampage’ Jackson and Alistair Overeem.
After an initial setback loss to Forrest Griffin, Rua would cement his reputation as the consensus best Light-Heavyweight in the world with a victory over Lyoto Machida at UFC 113 in May 2010 to capture the UFC Light-Heavyweight Championship.
His first title defence would be against surging contender Jon ‘Bones’ Jones after Jones’ training partner Rashad Evans had to pull out of the scheduled title bout with a knee injury. Jones would step in on a month’s notice and dethrone Rua in round three of their fight to capture the title.
This fight was a true passing of the torch as with this victory, Jones would become the youngest ever UFC champion at only 23. Jones would go on to largely be considered the greatest Light-Heavyweight of all time and still holds the title at the time of writing, only ever losing the title along the way due to disciplinary reasons.
#3. Isreal Adesanya vs Anderson Silva – UFC 234

The only fight on this list to not be contested for a championship, Isreal Adesanya vs Anderson Silva still represented a massive changing of the guard at 185 pounds. Anderson Silva is almost universally recognised as the greatest Middleweight of all time, if not the best mixed martial artist of all time.
When Silva’s record breaking 2,457 day-reign as UFC Middleweight Champion was brought to an end by Chris Weidman at UFC 162, many expected ‘The Spider’ to bounce back, despite being in his late 30s, many argued that Silva only lost to Weidman as he was caught with a knockout blow while taunting his opponent. The rematch with Weidman would prove catastrophic however, as Weidman would check a leg kick from Silva in round two that left Anderson’s tibia and fibula broken clean in two, immediately stopping the fight.
It was an injury that many thought Silva may never recover from and his record after that fateful rematch has not been befitting of his legendary status. A comeback win over Nate Diaz was overturned to a no-contest after both fighters tested positive for banned substances, which was followed by back-to-back losses to Michael Bisping and Daniel Cormier. Silva would score a unanimous decision victory over Derek Brunson at UFC 208, his first victory in over four years.
When it was announced that Silva would be matched up against up-and-coming undefeated prospect Isreal Adesanya, it seemed clear that the UFC themselves was passing the torch on Anderson’s behalf, Silva was clearly past his best and Adesanya looked, and turned out to be, a future UFC Middleweight Champion. It seemed that the UFC was looking to christen a new Anderson Silva, a similarly lean, stylistic, accurate striker with a supreme level of confidence and belief in his abilities.
In situations such as these, an aging legend being matched up against a dangerous prospect; many fight fans will simply hope that their beloved heroes can simply survive and not absorb too much damage. Silva would not listen to those fears as the two men would go to war over three rounds, Adesanya would win the fight via unanimous decision, catapulting himself into title contention, but Silva had put on an admirable performance, showing glimpses of his former glory. Both men would bow to each other after the fight, crowning a new star in the division with a single image.
#2. Amanda Nunes vs Ronda Rousey – UFC 207

It seems crazy to look back on it but before Ronda Rousey broke into the mainstream and became one of the biggest stars in the sport with her feuds with Miesha Tate and Cris Cyborg in Strikeforce, Dana White was filmed in 2011 by TMZ saying that women would never fight in the UFC.
This left promotions like Strikeforce and all-women’s promotions like Invicta to shine with influential women’s fighters such as Gina Carano, Julie Kedzie, Marloes Coenen and the aforementioned Tate and Cyborg. When Strikeforce folded and was then absorbed by the UFC, Dana White would see Ronda’s star power, and award her with the inaugural UFC Women’s Bantamweight Championship, as Rousey was the last holder of the division’s championship in Strikeforce.
The rest is history and has been told and retold over and over again. Ronda dominates both in and out of the octagon, sets and still holds the record for most consecutive title defences and suffers a shocking head-kick KO against Holly Holm at UFC 193.
A full year after one of the most shocking upsets the sport had ever seen, Rousey would try to reclaim her crown against newly-minted champion Amanda Nunes at UFC 207, the promotion for the event was focussed almost entirely around Rousey’s return, the tagline for the pay-per-view being ‘She’s Back’.
Nunes at this point in her career had scored impressive victories over former and future stars such as Miesha Tate, Valentina Shevchenko, Germaine de Randamie and Julia Budd but with Holm losing the title in her first defence against Tate, and Tate then losing in her first defence against Nunes, it seemed to some that the division was wide open without Rousey and she was still the only queen the division had known.
So, when Nunes dismantled Rousey in the first minute of the fight, it was clear that she had the potential to make the division her own. Looking at where Nunes is now, it is difficult to argue that this wasn’t a changing of the guard, Nunes is currently on a 11-fight win streak, holds championships in two weight divisions and is considered by many to be the greatest female fighter of all time.
#1. Georges St-Pierre vs Matt Hughes 2 – UFC 65

At UFC 50, in only his third fight in the UFC and his eighth professional fight in general, Georges St-Pierre was faced with an unenviable task, take down arguably the best pound-for-pound mixed martial artist on the planet and potentially the greatest Welterweight of all time, Matt Hughes. By contrast, Hughes went into UFC 50 with a record of 37-4, boasting wins over Sean Sherk, Carlos Newton and Frank Trigg.
GSP would put up an admirable performance against Hughes but would tap out to an armbar late in the first round. St-Pierre would admit afterwards that he had lost before the fight had even started, saying that he regarded Hughes as an idol and was in awe of him and did not see him as someone that he could beat; this being evident from the fact that GSP could not even look Hughes in the eye while the referee was giving his pre-fight instructions.
St-Pierre would rebound with five straight victories, setting up a rematch with Hughes at UFC 65, where the Canadian challenger would fare much better. GSP would drop Hughes late in the first round and finish the fight in the second with a picture-perfect head kick and follow-up strikes to force the referee to stop the fight.
GSP would lose the championship in his first defence in an upset loss to Matt Serra, where he admitted that he had underestimated his opponent going into the fight. This would set up a rubber match between St-Pierre and Hughes at UFC 79. GSP would put an exclamation point on his trilogy with Hughes by defeating him in the same way that he had lost their original encounter, with an armbar.
St Pierre would avenge his loss to Matt Serra by TKO at UFC 83 to reclaim the UFC Welterweight Championship and after nine straight title defences, would seemingly retire following a Middleweight Championship victory over Michael Bisping in 2017 having never lost another fight.