Before their first dance of the night, a pre-taped package addressed Kordei's ankle injury, which occurred when she was practicing a toe-touch in the dance studio with her pro-partner Val Chmerkovskiy.
"All of my body weight came down on it and it really hurt," the singer recalled.
"I just feel terrible. This is a week that's already really intense and she's never gonna admit that she's hurt," Chmerkovskiy told the DWTS cameras in a solo interview.
However, when it came time to dance, the Fifth Harmony singer was all smiles as she and Chmerkovskiy delivered a seriously skillful quickstep set to "Check It Out" by Oh The Larceny, and her footwork was as on-point as ever.
"I don't think your ankle knew it was hurt," host Tom Bergeron quipped as the couple finished their performance.
Kordei stunned in a skin-tight black bodysuit while Chmerkovskiy bared his chest with an unbuttoned black shirt. However, despite how amazing both dancers looked, some of the judges felt the bodysuit made a few of the dancers' mistakes all the more obvious.
"One thing that kind of threw me off a little bit is that you didn't have your skirt, and so it was very vulnerable for you, so sometimes I did see lack of body contact," Julianne Hough explained. "And because [we] have such high expectations of you, I definitely saw [mistakes]."
Judge Len Goodman, who has been one of Kordei's toughest judges, agreed with Hough, adding, "I like the catsuit, you look great in it, [but] costumes are a bit like makeup -- they can cover up a lot of mistakes and blemishes," and that the outfit allowed the judges to see some of the minor flaws.
While Goodman and Hough awarded the couple nines, Bruno Tonioli and Carrie Ann Inaba had nothing but praise for the pair and gave them 10s for a total score of 38 out of 40.
For their second dance, a freestyle routine set to "What the World Needs Now Is Love" by Andra Day, Kordei and Chmerkovskiy delivered a heartfelt performance dressed to the nines, with the singer rocking a flowing white, semi-sheer gown, while her partner looked like a million bucks in a crisp white tux.
As they danced, the couple was joined by a pair of pre-teen performers dressed like their adorable doppelgangers, and the touching routine was as sweet as could be.
"Thank you guys for giving me my light. I just wanted to say that to every person in here," Kordei said as she tried to catch her breath after the dance. "I feel like I'm a different person walking out than when I came in."
While the couple came just short of a perfect score for their first dance, they made up ground with their freestyle, and walked around with four 10s for a combined score of 78 out of 80 for the night.
Kordei, Jennings and Ross will continue battle it out for the coveted Mirrorball trophy in the second night of the Dancing With the Stars finale on Tuesday at 8 p.m. ET/PT on ABC.