Namajunas was scheduled to face Jéssica Andrade for a rematch on April 18, 2020 at UFC 249. On April 8, 2020, Namajunas withdrew from the event, with her manager citing a pair of deaths in the family related to the COVID-19 pandemic as the reason.

In her second title defense, Namajunas faced Jéssica Andrade in the main event at UFC 237 on May 11, 2019, in Andrade’s home country of Brazil, in what would be Namajunas’ first MMA fight outside the United States. Despite dominating the Brazilian throughout the first round and the beginning of the second, she lost the fight by KO via a slam in the second round. This fight earned her the Fight of the Night award.

In the first defense of her title, Namajunas faced Jędrzejczyk in a rematch that took place on April 7, 2018, at UFC 223. She won the fight by unanimous decision. Namajunas spent the remainder of the year recovering from a lingering case of spinal stenosis from a C6 vertebral compression fracture, symptoms of which manifested while training with Valentina and Antonina Shevchenko in 2017, and had intensified during training camp for UFC 223.

Namajunas faced Michelle Waterson on April 15, 2017, at UFC on Fox 24. Namajunas dropped Waterson with a head kick, and won by submission due to a rear-naked choke in round 2, marking the 5th submission finish in her career.

Namajunas faced Strawweight champion Joanna Jędrzejczyk at UFC 217 at Madison Square Garden in New York on November 4, 2017. She came in as a big underdog against the undefeated champion. However, Namajunas upset the MMA world when she knocked Jędrzejczyk down, once behind the ear and then again with a left hand to the chin. She won the fight by KO in first round to be crowned the new UFC Women’s Strawweight Champion. This win also earned Namajunas her second Performance of the Night bonus award. This was Namajunas’ first knockout victory in her professional career (2 TKO-wins as an amateur). Her victory was immediately declared one of the biggest upsets in UFC history. At the UFC 217 post-fight press conference, Namajunas stated that she intended to use her champion status as a platform to spread awareness of mental illness.

On April 16, 2016, Namajunas faced the still-undefeated Tecia Torres at UFC on Fox 19 in a rematch of their 2013 fight at Invicta FC 6. Namajunas won the fight via close but unanimous decision.

On July 30, 2016, Namajunas fought Karolina Kowalkiewicz at UFC 201 in a match regarded as a title eliminator. Kowalkiewicz defeated Namajunas via split decision. Both participants were awarded Fight of the Night for their performance.

Namajunas was expected to face Nina Ansaroff on May 23, 2015, in a preliminary bout at UFC 187. Prior to the fight, Ansaroff missed weight by 4 pounds and was fined 20 percent of her fight purse. The bout was scrapped entirely a couple hours before the event, as Ansaroff was declared medically unfit to compete due to illness. According to Ansaroff’s camp, she contracted the flu the week before, and the weight cut exacerbated the illness, forcing Ansaroff to abandon her weight cut early, and ultimately withdraw from the fight. Though the fight couldn’t take place, Namajunas was paid her full fight purse (show- and win money).

Namajunas fought Angela Hill on October 3, 2015, at UFC 192. After some back-and-forth striking exchanges on the feet, Namajunas took Hill down with a trip off a punch. As Hill stood up, Namajunas quickly secured a rear-naked choke, submitting Hill in the first round.

In a quick turnaround, Namajunas faced streaking prospect Paige VanZant in the main event of UFC Fight Night 80 on December 10, 2015, replacing an injured Joanne Calderwood. Namajunas dominated VanZant throughout the fight, out-striking her consistently and landing eight takedowns. She attempted three submissions—two armbars and a rear naked choke—before she won the fight midway through the fifth round via submission due to a rear naked choke. The win also earned Namajunas her first Performance of the Night bonus award.

Namajunas faced Carla Esparza at The Ultimate Fighter: A Champion Will Be Crowned Finale on December 12, 2014, for the vacant UFC Strawweight Championship. Namajunas lost the fight as she was submitted via rear-naked choke in the third round.

I got it [nickname] from my neighborhood friends. When I was little, I was the only white girl, I was smaller than everyone else, and for some reason I just acted harder than everybody else — just fearless, you know? So they kind of dubbed me that because of the intimidating scowl I always had on my face. That’s what gave me that name.

She made her professional debut against Emily Kagan at Invicta FC 4: Esparza vs. Hyatt on January 5, 2013. After two back-and-forth rounds, Namajunas was able to secure the victory via submission due to a rear-naked choke in round three. The victory in her pro debut also earned her the Submission of the Night bonus.

In her second professional appearance, Namajunas faced Kathina Catron at Invicta FC 5: Penne vs. Waterson on April 5, 2013. She won the fight by submission due to a flying armbar just 12 seconds into the first round. This performance garnered Namajunas her second Invicta Submission of the Night award.

Namajunas fought fellow undefeated prospect Tecia Torres at Invicta FC 6: Coenen vs. Cyborg on July 13, 2013. Namajunas lost the fight by unanimous decision.

On December 11, 2013, it was announced that Namajunas was signed by the Ultimate Fighting Championship (UFC) along with 10 other strawweight fighters to compete on season 20 of The Ultimate Fighter, which would crown the first-ever UFC strawweight champion.

Namajunas began competing in MMA as an amateur in 2010. She trained under Greg Nelson at Minnesota Martial Arts Academy. She racked up a perfect amateur record of 4-0 with 2 wins by TKO and 2 by decision. Both of the finishes came in the first round.

Rose Gertrude Namajunas ( /n ɑː m ə ˈ juː n ə s / ; born June 29, 1992) is an American mixed martial artist. She is currently signed to the Ultimate Fighting Championship (UFC), where she competes in the women’s strawweight division. Namajunas is a former UFC Women’s Strawweight Champion. As of February 10, 2020, she is #2 in the UFC women’s strawweight rankings and #6 in UFC women’s pound-for-pound rankings.

Namajunas was born in Milwaukee, Wisconsin on (1992-06-29 ) June 29, 1992, to Lithuanian parents. She was named Rose (Lithuanian: Rožė) in honor of her great-grandmother Rožė Gotšalkaitė Namajūnienė, whose husband was an independent Lithuania military officer. He was killed by the Soviets near his house in the temporary capital of Kaunas, Lithuania. Rose Namajunas regularly visits Lithuania and understands the Lithuanian language, because she communicates in it with her grandparents.