Top 10 MMA stories of 2020: 5-1

From Conor McGregor's triumphant return to Khabib Nurmagomedov's surprise retirement, a lot happened in mixed martial arts this year.

Here is part two of theScore's top 10 stories of 2020.

10-6 | 5-1

5. Stars speak out against UFC

Multiple high-profile fighters were at odds with the UFC at certain points of 2020.

Jon Jones was involved in a public spat with UFC president Dana White in May over his rumored financial demands for a potential heavyweight bout against Francis Ngannou.

The former light heavyweight champion eventually dared the promotion to release him and said he wouldn't step into the Octagon again until he gets a better contract.

A week later, welterweight star Jorge Masvidal decried the promotion's revenue share with its fighters - which is reportedly no more than 20% - and suggested the UFC refused to offer him what he believed he was worth.

On a somewhat similar note, Conor McGregor engaged in a heated back-and-forth with White in September.

The former two-division champion revealed private messages between him and White from earlier in 2020, which the UFC president called "one of the dirtiest things you can do." McGregor then accused White of lying about the Irishman turning down fights.

Rarely have we seen fighters speak out against the UFC at all, so it was surreal to witness two massive stars in Jones and Masvidal call out the promotion in the same year.

4. Chimaev's rise

At the beginning of July, Khamzat Chimaev was a complete unknown to the vast majority of MMA fans.

By the end of December, he's become the hottest prospect in the UFC and appears destined to be a top contender - and maybe even a champion - sooner rather than later.

Chimaev's sudden rise to fame was spectacular to watch.

"Borz" made his Octagon debut on a week's notice in July, destroying John Phillips en route to a second-round submission. The Russian-born Swede made the quickest turnaround in UFC history 10 days later, finishing Rhys McKee in the first round.

Chimaev's biggest test to date came in September against veteran middleweight Gerald Meerschaert, whom he knocked out in 17 seconds. Not only did Chimaev win his first three UFC fights in a 67-day span, but he barely got touched.

The promotion put Chimaev on the fast track after that victory, booking a pivotal welterweight clash against No. 3-ranked contender Leon Edwards. It's unknown when that fight will take place, as Chimaev had to withdraw amid a slow recovery from COVID-19.

Many people have compared Chimaev to lightweight champion Khabib Nurmagomedov - one of the most dominant fighters in MMA history - but with the added threat of Chimaev's ferocious knockout power. The speed with which Chimaev went from an unknown to rising star was unprecedented. His rise was one of the stories that shaped 2020, and it's almost a guarantee the 26-year-old will have a huge impact on 2021 and beyond.

3. McGregor's return

After sitting on the sidelines for more than one year, the sport's biggest superstar made his successful return in January.

Conor McGregor faced Donald Cerrone at welterweight in the UFC 246 main event. The former two-division champion made up for lost time, finishing "Cowboy" with strikes in 40 seconds.

This was a huge victory for McGregor in many ways. It was his first win in the Octagon since 2016, when he stopped Eddie Alvarez to become the first simultaneous two-division champion in UFC history.

But it also took the focus off McGregor's legal troubles, which dominated headlines in 2019. For the first time in a while, McGregor felt like the biggest star in MMA, not someone infamous for punching a man at a pub.

Though the Irishman didn't come close to completing his three-fight "campaign" in 2020, the impact of his return can't be overstated. When McGregor - who could potentially fight for the lightweight title in 2021 - is active and winning, that means big business for the UFC.

2. UFC 1st to return amid COVID-19 pandemic

The coronavirus pandemic impacted mixed martial arts just like everything else. The UFC was forced to pause its operations for nearly two months starting in March.

However, White was eager for the UFC to be the first major sports league back. And he succeeded.

During a time when the NBA, NHL, PGA Tour, and MLB were still on hold, the UFC returned May 9 for an interim lightweight title bout between Tony Ferguson and Justin Gaethje. The promotion hosted a trio of events at VyStar Veterans Memorial Arena in Jacksonville without fans and with COVID-19 measures in place.

By the end of May, the UFC returned to its hometown of Las Vegas and began holding events at the UFC Apex, a facility across the street from its corporate campus.

In the second half of the year, the promotion also hosted events on Fight Island - also known as Yas Island in Abu Dhabi, United Arab Emirates.

The pandemic presented many challenges to White and Co., even after the COVID-19 restart. Dozens of fights, including main events, were called off due to positive COVID-19 tests. The UFC - and other sports leagues - will more than likely continue to deal with positive tests well into 2021.

During a normal year, the UFC's biggest challenges may surround matchmaking, negotiations with fighters, and television rights deals. But in 2020, some of the biggest challenges were figuring out how international athletes could compete, how to limit positive COVID-19 tests, and how to proceed with events in the safest way possible.

On a positive note, the pandemic gave some fighters a chance to stand out. For instance, Kevin Holland competed five times from May to December. That likely wouldn't have happened during a typical year. Chimaev stepped into the Octagon twice in a 10-day span, and he could do it largely because both events were in Abu Dhabi.

The UFC has had its ups and downs during the COVID-19 pandemic, and that will be no different in 2021. But in White's eyes, you'll never be able to take away the fact that the UFC was back in business before any other major sports league.

1. Khabib, Cejudo, Cormier retire

Two reigning UFC champions and one former titleholder walked away from mixed martial arts in 2020.

Most notably, Nurmagomedov announced his retirement after a lightweight title defense against Gaethje at UFC 254 in October. Following the death of his father, the 32-year-old promised his mother it would be his last fight.

Nurmagomedov's surprise retirement shook up the MMA community, eliciting reactions from many top names, including former opponent McGregor. "The Eagle" is the only high-level fighter to retire with an undefeated record (29-0), and he moved up to the No. 1 position on the UFC's pound-for-pound rankings after the Gaethje win. Easily the most dominant, Nurmagomedov will go down as one of the greatest fighters of all time.

In May, Henry Cejudo announced his retirement after a bantamweight title defense against ex-champ Dominick Cruz at UFC 249.

This was arguably a bigger shock than Nurmagomedov stepping away, as there was no prior indication that Cejudo was nearing the end of the road.

"Triple C" left the door somewhat open to a return, and he's since expressed interest in a featherweight title shot against Alexander Volkanovski. But as of now, the former two-division champion is retired, and the bantamweight division moved on, with Petr Yan winning the vacant belt against Jose Aldo in July.

This year also marked the end for Daniel Cormier, who held belts at heavyweight and light heavyweight.

Prior to his trilogy bout against heavyweight champion Stipe Miocic at UFC 252 in August, "DC" made it known that it would be his retirement fight. Cormier, 41, lost to Miocic via unanimous decision and confirmed his retirement afterward.

Cormier's exit came later than expected, as he originally planned to retire in early 2019 after his 40th birthday. But his rematch with Miocic was pushed back to the second half of 2019, and after Cormier lost the belt by TKO, he wanted to come back for one more fight in hopes of retiring as the heavyweight champion.

The American Kickboxing Academy product accomplished so much in MMA in a relatively short window; he didn't make his professional debut until the age of 30. Cormier, who serves as a UFC color commentator, is a one-of-a-kind fighter and will go down as one of the best ever.