The UFC is as much a business as it is a sports league. That means you will never see a challenger promoted as anything other than an absolute killer and the biggest threat a champion has ever faced.

Going into UFC 254 at the Flash Forum in Abu Dhabi, UAE, Justin Gaethje was just that. A collegiate wrestling champion who came to the UFC having dominated the World Series of Fighting's lightweight division, he then lost two fights in an explosive manner and rebounded by winning four straight in an equally explosive manner. This May at UFC 249, he became UFC interim lightweight champion after dismantling Tony Ferguson over five rounds, ending an incredible eight-year winning streak in the process.

As a challenger going into the UFC 254's lightweight championship unification main event, Gaethje really was an absolute killer and the biggest threat the reigning champion had faced so far. This is important to know, not just to avoid revisionist hindsight but also to emphasize just how good his rival, Khabib Nurmagomedov, is.

Gaethje is a pressure fighter with heavy hands, and he spent all of round 1 being pressured and outboxed by Khabib. Gaethje tagged the champion with a few leg kicks and one or two hard right hands, but it did nothing to dissuade Khabib; he took the shots and forced Gaethje back to the cage, where he took him down and almost locked in an armbar as time expired.

At the start of round 2, Gaethje was already gassed. The constant backpedaling to escape Khabib had tired him out, and his leg kicks became too easy to time. After landing a particularly hard one, Khabib caught the next and instantly took Gaethje to the mat. Gaethje's greatest skill is his wrestling, and he was effortlessly outwrestled. Khabib had him wrapped up in a triangle choke in one minute and 34 seconds. Referee Jason Herzog missed the tap, and Gaethje went to sleep.

Immediately following this big win, Khabib collapsed onto the mat in tears and had to be comforted by the man he had just choked unconscious. It was an extraordinary sight. Going into this bout, the big question was the effect the passing of his father, mentor and coach Abdulmanap Nurmagomedov would have on Khabib. The answer is that he is very much his father's son.

Abdulmanap died on July 3, 2020, meaning this is the first fight Khabib had without his father's guidance. It would also be his only fight without his father's guidance. In his post-fight interview with Jon Anik, Khabib announced his retirement. He gave an emotional speech in which he said he had promised his mother he wouldn't fight without his father in his corner and will live up to his word. MMA retirements usually aren't worth the paper they're written on, but this one is different. As proven by the whole Conor McGregor drama, Khabib is fiercely loyal, so if he says he's done, he's done.

So where does this leave him on the Mount Olympus of MMA? The conversation of who is the greatest fighter of all time has typically revolved around four names: Fedor Emelianenko, Anderson Silva, Georges St-Pierre and Jon Jones. Each one of those men dominated their respective division through several generations of fighters and revolutionized the sport. Yet they all have blemishes. Fedor and Anderson ended their career with many bad, unnecessary losses. GSP was tapped by Matt Hughes and knocked out by Matt Serra, and Jones was taken to the limit by Alexander Gustafsson and only eked past Dominick Reyes.

Khabib retires undefeated at 29-0. Along the way, he was never cut or knocked down by an opponent and, according to the judges' scorecards, lost only two of the 61 rounds he competed in: round 3 against Conor and round 1 against Gethje, and in both fights, won by submission in the very next round. It's practically the perfect career, and at this point, there can be no doubt that Khabib Nurmagomdeov is the greatest of all time.