'The Voice': Hailey Mia Brings Kelly Clarkson to Tears With Stunning 'Elastic Heart' Performance

The 14-year-old singer's coach declared her the 'dark horse' of season 21 during Monday's live show!

The Voice's Top 11 of season 21 performed live on Monday night, and they may have saved the best for last!

Team Kelly's 14-year-old powerhouse Hailey Mia was the final performance of the night, and she took the stage for a soaring, heartfelt cover of Sia's "Elastic Heart" that brought her coach to tears and got everyone on their feet for a standing ovation. 

"I'm so proud of you," Kelly Clarkson raved of the performance. "I called this early on -- I thought, she's a dark horse. She's gonna come along and she's gonna be better and better. She's gonna be the one.

"I swear to you, you can make the finale," she added. "You just keep getting better and better each week. You're so phenomenal."

"You're so good at this that that was kind of hard to see you sad," Blake Shelton agreed. "We all love you so much and you did so good on that song, that it was literally so powerful that I got wrapped up in it going, 'Oh no, I don't want to see her sad!'"

"To have that kind of taste and charisma as a vocalist at 14 years old -- even at 30, is incredible," Kelly added. "You're 14, it's a godsend. I'm so blessed to have you on my team."

Team Kelly still has the season 21 advantage after her team swept the competition last week, with all four singers moving on to the Top 11 -- including the winner of the latest Instant Save, Gymani! Blake has three singers remaining in the competition, while John Legend and Ariana Grande have two apiece. 

Not only that, but two of the Top 11 singers on other teams -- Team Legend's Jershika Maple and Team Ariana's Holly Forbes -- were originally Team Kelly before getting stolen in the Battle and Knockout Rounds!

"There are some seasons when I end up with so many great singers that I get nervous about it, and you have to let some go to other teams," Kelly told ET following last week's live performances.

Though she definitely has a serious competitive drive, the performer and talk show host admitted, "I honestly don't care if Holly were to come back and beat me on Ariana's team or Jershika were to come back and beat me on John's team. We're all artists, we want them to thrive."

"Frankly that means you won the blinds," John noted. "Because that means that your team was so stacked with amazing people that they've lasted on the show no matter what team they were on."

The Voice airs Mondays and Tuesdays at 8 p.m. PT/ET on NBC. See more from this season in the video below!

RELATED CONTENT: