JoJo Siwa and Jenna Johnson On Getting Season's First Perfect Score on 'Dancing With the Stars' (Exclusive)

The pair left the judges stunned with their amazing routine during Monday's 'Dancing With the Stars.'

One flawless foxtrot! It was Grease Night on Monday's Dancing With the Stars -- which proved to be exactly what the show needed to see the season's first perfect score!

JoJo Siwa and Jenna Johnson hit the stage late in the episode, where they delivered a foxtrot set to "Look at Me, I'm Sandra Dee (Reprise)" from the 1978 classic musical. Siwa and Johnson donned pink ensembles for the emotionally stunning routine, and their flawless performance left the judges in awe.

ET's Lauren Zima spoke with Siwa and Johnson after the episode, and they opened up about the feedback from the judges and how it felt to get the first perfect score of the season.

"I think we put in so much work this week, and this number, oddly enough, has been the most challenging for me," Siwa reflected. "So, to see it be perfect on stage, it just shows that hard work, believing in yourself, and trusting the people that you're doing things with really pays off."

After their routine, Judge Len Goodman actually stood to deliver his feedback, and said in awe, "You affected my brain with the quality of the technique, you affect my heart with the artistry that you produced. It was superb."

"I absolutely love this partnership," Derek Hough marveled. "That was a moment!"

Bruno Tonioli said he was "still shivering," while Carrie Ann Inaba added, "You leave me nothing to say, other than this was perfection."

The pair ended up earning the very first perfect score of the entire season! Four 10s across the board for a flawless total of 40 out of 40, securing their place at the top of the leaderboard.

"Last week, Carrie Ann told us that we played it a little bit safe, and those words just, like, burned my soul," Johnson told ET on Monday. "So I came in on Wednesday swinging with this foxtrot choreography."

Luckily, the pair were able to make it work to great reward, and Johnson credits their chemistry as dance partners for their sucess.

"I really do feel like she has become a little sister to me," Johnson said, as Siwa rested her head on her shoulder. "It has been so magical to go through this whole experience with her."

Earlier in the week, ET was invited to the camera blocking for Grease Night, and she spoke with the pair about their performance for the special episode.

"I think, for us, this is the dance that we can relate to the most personally in our lives, especially with each other," Siwa said. "And so we've been able to almost not have to act this week."

She also recalled a personal breakthrough she had while rehearsing with Johnson, who asked her to take off a baggy shirt she was wearing at the time.

"[I said], 'I can't,' and she was like, 'Why?' and I was like, "'Cause I don't like the way I look under it.' She said to me, 'I am your partner. You have to trust me. Take it off like you're wearing something under.' Then I started crying and I took it off," Siwa shared. "And I went up to the mirror and she made me say a lot of things to myself that I had never said to myself, that I had never thought. And slowly but surely I'm finding myself, I'm finding how I feel about myself." 

The 18-year-old Internet sensation says she found strength in the lyrics of "Look at Me, I'm Sandra Dee (Reprise)."

"It's literally me, how I feel about myself and her being like, 'C’mon, now look at yourself, you're fine,'" she explained. 

Check out the video below to hear more from the pair.

Dancing With the Stars airs Mondays at 8 p.m. ET/PT on ABC.