SmackDown’s auspicious debut on Fox came with a hell of a surprise ending for the MMA fans among us. Former two-time UFC Heavyweight Champion Cain Velasquez made a shock appearance and floored Brock Lesnar, moments after the Beast had dethroned WWE Champion Kofi Kingston in quick fashion. Flanked by Rey Mysterio, Cardio Cain took Brock to the ground and administered multiple haymakers that put Lesnar on retreat.

It was a huge moment and demonstrated that Fox are serious about going all in on their new show. However, not everyone who follows WWE is a fan of MMA, leaving them bewildered as to why Velasquez showing up is such a big deal. If this describes you, we’ve got the perfect guide that sums up Cain’s legendary run in the UFC – including his mauling of Lesnar – to get you up to speed.

Velasquez entered the UFC with only two pro bouts under his belt in April 2009. As a two-time All American in collegiate wrestling and a black belt in Brazilian Jiu-Jitsu, his credentials were without question. As you might have guessed, Cain tore through the competition from the outset, ending his first three UFC fights by TKO and assembling an impressive 8-0 overall record.

En route to his first title shot, he’d defeat notable opponents such as Cheick Kongo, Ben Rothwell and the legendary Antônio Rodrigo Nogueira (or Big Nog, as MMA fans know him). This winning streak instantly put the young Velasquez on everyone’s radar, as he made mince meat of everybody standing in his way at heavyweight. It only made sense to pair him up with the champ.

Brock Lesnar was riding a wave of momentum himself when the fight was set. After debuting for the UFC in 2008, he’d win the HW strap in just his third UFC fight, defeating one of the all-time greats in Randy Couture that same year. He followed this up with successful defences against Shane Carwin and Frank Mir, the latter of which headlined UFC 100, the best-selling UFC pay-per-view in history up until then. Brock’s two consecutive defences stood as a record for nearly a full decade, until Stipe Miocic clocked a third defence against Francis Ngannou in 2018.

Lesnar had shocked the world. He’d transitioned from the “fake” world of pro wrestling and snatched the top prize in the biggest MMA organisation on the planet. He was an outsider, a renegade. The UFC fans were sharply divided on his presence and what he contributed to the sport. There were objections to him receiving a title shot so early into his run, as well as dismay over his unsportsmanlike behaviour after pummelling Frank Mir. He was an outspoken, brash individual who needed to be put in his place.

Enter Cain Velasquez, the hot prospect who had finished all but one of his fights by KO/TKO. At UFC 121 on October 23, 2010, the Mexican-American mauler not only relieved Brock Lesnar of his title, he destroyed him for it. Before the first round had ended, Cain had Brock on the mat and was sending down an endless barrage of blows. Referee Herb Dean pulled Velasquez off and stopped the fight before any more damage could be administered. The new champion walked away with hardly a mark on him, the defeated Lesnar’s face was a mess of blood and welts. You know that large scar underneath Brock’s left eye that he didn’t have when he left WWE in 2004? Yeah, that was Cain.

The fight wasn’t even competitive. Brock managed to secure a single-leg takedown on the challenger, but the superior wrestling technique of Velasquez allowed him to escape with relative ease. The rest of the bout was Cain lighting up Lesnar with constant combination strikes both on the feet and the ground. It’s one of the most thorough beatdowns of a Heavyweight Champion that’s ever been seen in the UFC. Suddenly, MMA had a new star and Brock Lesnar’s aura of invincibility had been shattered.

Brock Lesnar was never the same after fighting Cain. His diverticulitis saw him take over a year out of the Octagon. His return bout against Alistair Overeem in 2011 ended in even more embarrassing fashion with another first round TKO. Brock would then retire from the sport and hasn’t scored an official win since 2010 (his return bout against Mark Hunt in 2016 was retroactively made a no-contest after a doping violation).

Meanwhile, Cain Velasquez had his first defence lined up for the first ever UFC on Fox event in November 2011. His opponent was far from a walk in the park. Junior dos Santos had a 13-1 record and was feared for his vicious knockout power. Any JDS fight could end in an instant if he tagged you with a big shot. But this was Cardio Cain, this was the undefeated world champion who made Brock Lesnar his ragdoll. This was a man whose gas tank never emptied, who could swarm opponents with constant forward pressure. This would be his true coronation as the face of the heavyweight division, surely?

To the absolute shock of just about everybody, Cain lost. Badly. In fact, it only took one minute and four seconds for JDS to knock the champ out cold and claim the title for himself. To this day, it’s one of the most notable upsets in UFC history. Not because dos Santos was a bad fighter, he’s one of the best to ever do it. But the way he won against a man who looked to be unstoppable saw many a jaw hit the floor.

Six months after losing his belt, Cain Velasquez started on the path to redemption, finishing the imposing Antônio Silva in a little over three minutes to get back in the win column. Meanwhile, JDS registered his first defence of the belt over Frank Mir on the same night. The two former opponents had scored major wins in the final two fights of UFC 146 and the rematch was all but confirmed by UFC President Dana White after the show.

At UFC 155 in December 2012, Cain Velasquez got his revenge in the most convincing of fashions. If Junior dos Santos is the master of the early knockout, then Cain is the master of prolonged mauling. Over the course of a full five-round fight, Velasquez dominated the champion. Landing 111 significant strikes and 11 takedowns, Cain took the bout by an unquestionable unanimous decision. He had dismissed the first loss as a fluke and regained his throne, avenging the only loss he’d ever been handed.

Cain would go on to have the run he was expected to have after this. In a rematch with Silva in May 2013, he gained a TKO in under 90 seconds to retain his crown. In October of that same year, the rubber match with dos Santos took place.

This fight was even more one-sided than the first, with Cain treating his opponent like how a dog treats a chew toy. Mercifully, the champ ended proceedings in the fifth round with a brutal slam to the mat, followed by a paralysing punch for the TKO. JDS was bleeding heavily with his left eye swollen completely shut. Cain took some licks as well, but there was no question over who the better man was. Dos Santos might have beat Velasquez in a minute, but Cain beat him over the course of almost 50.

Sadly, the high of winning the trilogy with JDS would be the last time Cain Velasquez was on top. The major contributor to his decline was the injury bug. Cain would only fight three more times after October 2013, taking long periods of time out between contests. His title defence against Fabricio Werdum came a year-and-a-half after the final JDS fight, owing to a torn meniscus delaying proceedings. Werdum is one of the best heavyweights there’s ever been, but Cain still walked into the fight as the favourite.

Unfortunately for the champion, the location of the battle played a key factor in the outcome. Despite being of Mexican heritage, Velasquez did not live in Mexico. The high elevation of the nation’s capital where the bout took place took a real toll on Cain’s cardio, a tragic irony when you consider the praise his conditioning received. Fabricio Werdum had spent far longer in Mexico City to train for the fight than Velasquez, meaning the Brazilian’s body could acclimate to the thinner air and function on less oxygen. Cain would gas himself out early in the fight due to a lack of experience fighting at high altitude, and Werdum choked him out in the third round to take the belt.

Over a year after the loss, Velasquez handily disposed of Travis Browne (who wrestling fans might know as Ronda Rousey’s husband) at UFC 200. A first round TKO was business as usual, and it seemed as though Cain was back on the path to greatness. What UFC fans didn’t know was that they wouldn’t see the man step into the cage for another two-and-a-half years. Between July 2016 and February 2019, attempts to set up a rematch with Werdum routinely fell through. Constant injury and health issues for Cain plagued the former two-time champ, and it felt like he’d never fight again.

Well, he would, for 26 seconds. Cain Velasquez vs. Francis Ngannou was set for the first ever UFC on ESPN card. History was repeating itself for Cain, who walked into the main event of a major show debuting on a new network and ate an early knockout. In less than half a minute, the Cameroonian powerhouse Ngannou caught Cain with a massive shot that threw him through a loop.

The fans who had waited patiently to see their hero make his glorious return were treated to a deflating performance. Cain’s homecoming to the state he was raised, Arizona, ended with him being disposed of by UFC’s newest heavyweight monster. A man who had been so dominant and intimidating had seen the latter part of his career defined by injuries and bad luck. It was the most frustrating fall from grace for an athlete: one that was caused by the universe working against them.

Cain’s return to the UFC was the first in a four-fight contract, but that seems to be on hold now in favour of his new passion: professional wrestling. Velasquez had a private session at the WWE Performance Center in July 2018 and attended NXT tapings the same month. Rumours began swirling that he was working towards a debut in the squared circle, and the major promotions were sure to be in a bidding war for his services.

Cain would make his debut at AAA’s Triplemania XXVII, sporting a luchador mask and teaming with Cody Rhodes and Psycho Clown. Fans were naturally uncertain about the former UFC star’s ability to perform in a wrestling ring, but he quickly put those doubts to bed. Velasquez displayed surprising athleticism and high-flying ability, wrestling in a traditional lucha style that caught the wrestling world off guard.

Last week, it all came full circle. Cain Velasquez made his debut in WWE. The man who sent Brock Lesnar on the path to retirement from MMA showed up on SmackDown and picked up right where he left off with Brock. If you’re not a follower of the sport, then this rundown of Cain’s career should inform you why he’s being treated as a major threat to the new WWE Champion. His instant ascension to a top spot is fair to question, but his dedication to this new gig and legitimate credentials are nothing to sneer at.

One thing is for sure: the man who took Brock Lesnar’s soul is back to finish what he started.