As 2010 dawned, Fedor Emelianenko was the premier fighter in the sport. He was 33 years old and boasted a professional record of 31-1 with one no-contest. The blemishes on his record consisted of a cut stoppage against Tsuyoshi Kosaka that had hinged on a technicality, and a no-contest—again due to a cut—against Antonio Rodrigo Nogueira, a man he beat decisively in their other two meetings. In other words he was, for all intents and purposes, undefeated. Leaving aside the cut stoppages, Emelianenko’s rare moments of actual adversity had come in victories over opponents such as Ricardo Arona, Kazuyuki Fujita and Kevin Randleman.

Emelianenko seemed more than a mere fighter, as if being the greatest heavyweight in mixed martial arts history wasn’t enough. To many fans, “The Last Emperor” was an avatar of a full-blown divide in the sport: the Ultimate Fighting Championship vs. the world. As the UFC had spent the second half of the 2000s skyrocketing on the momentum of “The Ultimate Fighter,” while Pride Fighting Championships had foundered in a sea of scandal and unsustainable expenses, most of Pride’s top-shelf talent outside of the lightweight division had ended up in America. While Wanderlei Silva, Mauricio Rua and Dan Henderson came (or came back) to the UFC, joining early ship-jumpers like Mirko Filipovic, Quinton Jackson and Anderson Silva, Emelianenko remained aloof. Negotiations apparently took place more than once, but there was an insurmountable obstacle in the form of Emelianenko’s loyalty to his M-1 cohorts and the UFC’s absolute unwillingness to co-promote with M-1 or anyone else.

So it was that Emelianenko came to stand—at least in the eyes of the “Pride Never Die” contingent—for an alternative to the UFC’s growing hegemony over the sport. For as long as the enigmatic Russian was out there winning fights, there was always an easy response: “Sure, the UFC bought out Pride, but Fedor could beat anyone in the UFC.” That argument was bolstered by Emelianenko’s post-Pride world tour, which included humiliating first-round finishes of Tim Sylvia and Andrei Arlovski, who, along with Randy Couture and Frank Mir, had defined the cream of the UFC heavyweight crop during Emelianenko’s reign in Pride. For MMA media members, and fans sufficiently embedded to care about the business side of the sport, Emelianenko represented an alternative in the board room as well as the cage. While the UFC had no interest in co-promotion with M-1, Emelianenko’s 2007-2010 record includes stops in such promotions as Dream—an attempt to resurrect Pride in all but name—as well as UFC antagonists Affliction and Strikeforce, both of which were more than happy to cut Emelianenko’s people in on the deal.

None of this is to say that Emelianenko looked unbeatable by 2010. In much the same way that insiders and experts had seen the devolution of Mike Tyson for several years before his upset at the hands of Buster Douglas, Emelianenko’s game had been slipping. In broad strokes, the decline had even been similar, as both champs had gradually moved away from the skill sets that had brought them to the pinnacle of their sports in favor of the easier approach of headhunting. In Tyson’s case, he had abandoned his diligent body work and head movement, while Emelianenko had devolved from a great ground-and-pounder with surprising punching power, to a huge puncher with somewhat neglected takedowns.

However, as Strikeforce/M-1 Global: Fedor vs. Werdum drew near on June 26, 2010, even those sharp minds who thought “The Last Emperor” might be ripe for an upset would have been hard pressed to name Fabricio Werdum as the man to pull it off. On the face of things, Werdum faced a miserable matchup in Emelianenko, and in fact “Vai Cavalo” might have been at the worst stylistic disadvantage of any Top 10 heavyweight against the pound-for-pound stalwart. In contrast to his second UFC run, the 2010 version of Werdum was a decent but imperfect striker who had been flatlined by hard punchers like Junior dos Santos and rendered completely inert by more experienced standup fighters like Arlovski. And while Werdum was already considered one of the greatest heavyweight grapplers in MMA history, that offered little hope against a man who had fearlessly punched the head of “Big Nog” into paste twice.

With the stage thus set, Werdum entered the round Strikeforce cage in San Jose, California, as a roughly 5-to-1 underdog against Emelianenko. For the record, there is nothing about the lead-up to the fight that is especially aberrant in hindsight. While Werdum showed up in good physical shape, he was not shockingly fit, and Emelianenko looked much the same as he had throughout his late- and post-Pride reign. In other words, if you had been disinclined to put money on the fight ahead of the official weigh-ins the day before the event, there was nothing that would have changed your mind by fight night.

After a couple of early exchanges on the feet, Emelianenko dropped Werdum with a flurry of punches. Werdum would claim afterwards that he had played possum, falling down from punches that had not actually hurt him in order to draw Emelianenko into the ground game. That is impossible to confirm, but considering Werdum’s willingness flop into guard—both before and after that night—if he is being truthful, at least he got to hone his acting chops. What is possible to confirm is that Emelianenko immediately pounced, trying to finish. Whether the Russian was fooled by Werdum’s ruse or simply lulled from a decade of beating the living crap out of everyone he knelt over is a question for the ages, but the result was the same: The fully alert Werdum was simply a step ahead of Emelianenko from the moment the action hit the floor. The Brazilian threw his legs up for a shockingly fast triangle—especially by the standards of 240-pound men—and as Emelianenko defended, he threatened with an armbar from the same position. After a bit of jockeying, during which the announcer booth went into meltdown, “The Last Emperor” realized the futility of the situation, and he may have been the first person in the building to do so. At a minute and nine seconds of the first round, Emelianenko gave a single, unhurried tap on the leg of the challenger and just like that, an era ended.

For hardcore fans, the aftermath of Emelianenko's loss surpassed anything that had happened in the history of the sport, and Werdum truly shocked the world—of MMA, at least—in a way that had never happened before. Speaking personally as someone who was present for B.J. Penn’s upset of Matt Hughes, Matt Serra’s upset of Georges St. Pierre and Fedor-Werdum, only one of those three fights completely crashed the Sherdog forums. Regardless of whether you were gleeful—remember Dana White tweeting nothing but a smile emoji?—or crestfallen, it felt like the end of an era because it was.

In the following days, Emelianenko maintained the dignity of a dethroned emperor. He admitted that he had made a mistake by diving into Werdum’s guard, uttered the now-canonical “The one who doesn’t fall, doesn’t get back up,” and otherwise declined to make excuses. Werdum, for his part, partied like it was 1999 but, outside of a brief and forced effort to assert that his long-held nickname was a reference to the triangle-or-armbar dilemma he had presented to Emelianenko, let the accomplishment stand on its own.

It was the most important single fight outcome of the post-“The Ultimate Fighter” era in mixed martial arts. The loss of Emelianenko’s mystique—especially when he lost his next two fights—removed the main pillar of support for any MMA promotion seeking to go head-to-head with the UFC. Considering that Affliction had gone under simply for failing to make the fight between Emelianenko and Josh Barnett happen while he was still essentially unbeaten, it is not at all surprising that Strikeforce was doomed. While Emelianenko eventually followed Strikeforce boss Scott Coker to Bellator MMA—where he has experienced a modestly impressive final act to his career—the story was already written in outline ten years ago today at Strikeforce: Fedor vs. Werdum.