2021 proved to be a successful and entertaining year for the UFC. UFC debuts, fight of the night performances, and numerous successful PPV events have set the UFC up for an even greater in 2022. Throughout 2021, there were several memorable moments in the UFC that made 2021 particularly memorable

RELATED: 10 Funniest Fighters In MMA History

Fighters such as Dustin Poirier, Nate Diaz, and Kamaru Usman provided fans with some of the best fights of the year. 2021 will go down as one of the best years in UFC history. Without further ado, here's a look back at the very best moments of Ultimate Fighting Championship from the past year.

10 The Debut of Michael Chandler

The signing of Michael Chandler to the UFC was the most anticipated UFC debut in recent memory. The former Bellator standout is a three-time champion and had compiled a 21-5 record before signing with the UFC.

Chandler made his UFC debut against top-ranked lightweight Dan Hooker on the UFC 257 card. Despite giving up a significant height and reach disadvantage, Chandler knocked out Hooker in the first round and immediately captured the attention of UFC fans around the world. He fought three times in 2021 and provided fans with some of the most entertaining fights of 2021.

9 Nate Diaz Wobbling Leon Edwards in Round Five

Nate Diaz and Leon Edwards squared off in the Octagon at UFC 263 in a five-round match. Edwards used his prolific striking to continuously land combinations and leg kicks on the Stockton native for a majority of the bout.

RELATED: 10 Best Nicknames In MMA History

In classic Diaz fashion, Nate Diaz landed a perfectly time 1-2 combination in round five that stunned Edwards and sent those in attendance into an uproar. Despite losing by unanimous decision to Edwards on the scorecards, Diaz yet again proved just how tough, resilient, and entertaining he is.

8 Miesha Tate's Return to the UFC

Miesha Tate returned to the UFC after a five-year hiatus. She last competed at UFC 205 where she lost to Raquel Pennington via unanimous decision.

Despite a lengthy layoff, 'Cupcake' returned to action on July 17, 2021, and defeated Marion Reneau via TKO in round three. Tate faced Ketlen Vieira in her next UFC appearance and lost by unanimous decision. However, she showed the MMA community she still has what it takes to compete with the best in the world.

7 Dustin Poirier Knocking Out Conor McGregor in Their Rematch

2021 would prove to be the most lucrative year for Dustin Poirier. After establishing himself as one of the best lightweights in the world, Poirier earned himself a rematch with superstar Conor McGregor in the main event of UFC 257.

Poirier tactically attacked the leg of McGregor with kicks in round one to slow down the Irishman's movement. He flurried McGregor in round two and eventually landed a short left hook that sent 'Notorious' to the canvas. 'The Diamond' enacted his revenge after seven years of waiting and became a UFC superstar in his own right.

6 Kamaru Usman & Colby Covington Embracing After UFC 268

Kamaru Usman and Colby Covington are known for having one of the most intense rivalries in UFC history. Both men are extremely competitive, confident, and talented fighters that have shared the Octagon twice in two years.

RELATED: 10 Most Creative Strikers In UFC History

The two faced off in a rematch in the maint even for UFC 268 in November of 2021. Usman defeated Covington for a second time and defended his belt successfully. However, this time around, the bitter rivals embraced after their five-round war and acknowledged one another with respect. Seeing the two share such a moment after years of hate was special, to say the least.

5 Charles Oliveira Becoming UFC Lightweight Champion After 10 Years

It took Charles Oliveira over a decade to finally realize his dream of becoming a UFC champion. The Brazil native met Michael Chandler in the main event of UFC 262 and won by knockout to secure the UFC lightweight championship.

He defended his belt for the first time against Dustin Poirier at UFC 269 and secured the win by submission. Oliveira has established himself as one of the most exciting and well-liked champions going into 2022.

4 Glover Teixeira Becoming the Second Oldest Champion in UFC History

After trading wins and losses between 2016 and 2018, it seemed like a matter of time before Glover Teixeira's retirement fight would be on the dock. Instead, the Brazilian defied father time and compiled a five-fight win streak that secured him a title shot against Jan Blachowicz at UFC 267.

RELATED: 10 Best Body Strikers In UFC History

Teixeira used his impeccable grappling abilities to secure a dominant submission victory over the champion and become the new UFC light heavyweight champion. At 42 years old, he became the second-oldest champion in UFC history after Randy Couture.

3 Kamaru Usman Knocking Out Jorge Masvidal In Front of a Sold-Out Crowd

Many thought Jorge Masvidal would give Kamaru Usman a run for his money in their rematch due to having a full training camp. In their first meeting, Masvidal took the fight on short notice and cut a tremendous amount of weight in five days to be able to compete.

The pair met at UFC 261 which would be the first UFC event to have fans in attendance since early 2020. In round two, Usman hit Masvidal with a thunderous right hand that knocked the challenger out on his feet. The knockout is widely considered the greatest knockout of 2021 and further elevated Usman's status as a champion and superstar.

2 Rose Namajunas Reclaiming the UFC Women's Strawweight Championship

Rose Namajunas's thrilling upset knockout victory over Joanna Jedrzejczyk to claim the UFC strawweight championship back in 2017 is one of the most memorable events in MMA history. After losing the title to Jessica Andrade in 2019, 'Thug Rose' defeated Andrade in a rematch to earn herself a second title shot against Zhang Weili.

Namajunas stunned the MMA community by knocking out Weili in round one with a head kick to reclaim the belt. After the fight, Namajunas's coach famously asked her, "Who is the best?" She responded, "I am the best." It had to be one of the coolest moments in championship fight history and furthered the new champion's popularity. Namajunas rematched Weili in November of 2021 and successfully defended her belt by split decision.

1 Julianna Pena Upsetting Amanda Nunes to Claim the UFC Women's Bantamweight Championship

Many scoffed at the idea of Julianna Pena receiving a title shot against Amanda Nunes after only one win. Nunes was expected to quickly finish Pena and continue her reign as undisputed champion. The first round consisted of Nunes constantly battering Pena with powerful punches and dropping the challenger on more than one occasion.

In round two, Pena started to land clean 1-2 combinations that were visibly affecting Nunes. After consistently landing, Pena elected to take Nunes down and secured a rear-naked choke submission to become the new UFC women's bantamweight champion. Her victory is widely considered the greatest upset in UFC history and shocked the MMA world to its core.