Fabricio Werdum unified the title the last time the UFC had an interim heavyweight champion

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On June 13, 2015, both Cain Velasquez and Fabricio Werdum entered the Octagon with UFC gold. Velasquez was the lineal heavyweight champion and Werdum was the interim champion. Only one man could leave as the undisputed heavyweight champion of the world. Before we talk about the legendary fight that took place that fateful night in Mexico City, lets take a look back at what led to their being two belts in the first place.

Velasquez entered the UFC after only two professional fights and earned his shot at the belt after beginning his promotional tenure with six straight victories, five of those by way of knockout. In his first title fight, he defeated Brock Lesnar in just over four minutes. Velasquez lost his belt in his next fight to Junior dos Santos on the UFC's debut on Fox. Two fights later he would defeat dos Santos in the rematch to regain the belt. He would go on to defend it two more times before his showdown with Werdum.

Werdum had a very different path to a UFC belt. A multiple time Brazilian jiu jitsu world champion, Werdum had 12 professional fights before making his UFC debut, including a six fight stint in PRIDE Fighting Championships. His initial run in the organization did not live up to expectations and he was cut after going 2-2 in his first four fights.

The Strikeforce promotion, which was gathering the best talent in the world outside of the UFC, quickly signed Werdum. There he would notch his biggest victory to date with a submission of Fedor Emelianenko. It was Emelianenko's first loss in 10 years. After the UFC acquired Strikeforce, Werdum was back in the UFC.

Cain Velasquez and Fabricio Werdum fought for the undisputed heavyweight title

Werdum began his second stint in the UFC on a tear, defeating his first four opponents, including back to back main event victories over Antônio Rodrigo Nogueira and Travis Browne. This run set him up to coach The Ultimate Fighter: Latin America opposite Velasquez. The two were set to headline UFC 180, which also served as the finale of the show, with the heavyweight championship on the line.

Unfortunately, a knee injury forced Velasquez from the bout. Werdum would go on to defeat Mark Hunt with a flying knee and follow up ground and pound to capture the interim heavyweight championship. Seven months later, they would finally meet at UFC 188 in Mexico City.

Much had been made of Velasquez's cardio, even earning him the nickname "Cardio Cain". With Mexico City being over 7,000 feet above sea level, the question was whether Velasquez would be able to weaponize his cardio as he normally did. Werdum, having the experience of fighting in Mexico City before, decided to start training in the mountains near the city two months prior to the fight. This would end up paying dividends.

Velasquez began the fight at a blistering pace, forcing Werdum in to a fire fight. Werdum withstood the early onslaught only for Velasquez to secure a takedown 90 seconds in to the fight. Velasquez wanted nothing to do with Werdum on the ground and allowed him to stand back up. The fire fight continued, interspersed with periods of clinching along the cage.

The grueling pace of the opening round appeared to take a toll on both fighters as the action slowed down during the final minute of the round. The two combatants were bloodied and breathing heavily in their corners between rounds.

The second round opened with Velasquez continuing to walk down the interim champion. Werdum started landing his jab, which opened up the rest of his striking arsenal. As the round went on, Velasquez appeared to fatigue rapidly and Werdum was able to hurt him multiple times with a pin point accurate right hand. With just under 20 seconds left in the round Werdum landed a knee that floored Velasquez. Hurt badly, the champion was saved by the bell.

Before the start of the third round, referee Herb Dean called in the cage side doctor to make sure Velasquez was still fit to compete. The doctor gave him the go ahead and the fight resumed.

Velasquez continued to move forward, but was repeatedly met with Werdum's jab. At the urging of his corner, Velasquez shot for the takedown, but was unable to keep his opponent down. Back on the feet, Velasquez's shots looked much more labored. Despite a brief glimpse of hope from a head kick, Velasquez was unable to mount much offense. With just under three minutes to go, Velasquez shot sloppily for a takedown. Werdum seized the opportunity and Velasquez's neck. He secured the guillotine and the undisputed UFC heavyweight championship when Velasquez quickly tapped.

Up until this point, Velasquez was believed to be the most talented heavyweight the UFC had ever seen. He loss to dos Santos in their first fight was written off as a well timed punch that could happen to anybody. The beating that Werdum put on Velasquez changed that narrative. The injuries that plagued Velasquez throughout his career would catch up with him and he would only fight two more times before calling it a career.

Werdum, having finally obtained the undisputed title that had eluded him for so long, would have a short-lived reign at the top. He lost his belt in his first title defense when Stipe Miocic flattened him 11 months later at UFC 198 in Curitiba, Brazil.

Despite the quick declines of their careers after UFC 188, on June 13, 2015, we got to see the two best heavyweights in world battle it out to see who truly was the best on the planet. Though there were many variables, including the altitude and Velasquez's extended period of inactivity, that night Werdum won that crown.