In a pre-taped package played before her performance, Hale opened up on how life has changed since she won over the nation's heart during her first time around.
"Ever since AGT, I've been going everywhere," Hale shared, along with a montage of her talk show appearances and public performances. "I feel like I've grown a lot. I've been a better singer, a better performer, and now I get another shot at winning this thing."
The young hopeful -- who survived a battle with bacterial pneumonia when she was four that caused her kidneys to fail, and whose life was saved by a kidney transplant from her mother -- closed her segment with an inspiring message for everyone watching: "Never stop fighting, because you never know what will happen."
As the adorable young singer took the stage, judge Simon Cowell addressed the emotional challenge a young star faces when they come in second place on a show like AGT, and Hale said she'd come to earn her place among the best of the best.
"Tonight, I really am fighting for my place here at AGT: Champions, and I think this song really applies to what I'm doing here today," Hale said, before belting out the soulful opening lyrics of Rachel Platten's rock anthem "Fight Song."
The young songstress beautifully commanded the stage, using her larger-than-life voice to hit high notes that would be challenging for seasoned pros, and every minute of her performance proved just how much she'd grown since performing for the judges the first time around.
The audience was overjoyed by the performance, giving Hale a standing ovation. However, Mel B didn't seem as sure as everyone else.
"You have an incredible voice, and you're like a firecracker," Mel B said, before sharing the critique that she wished Hale had put her own signature flare on the song.
The comments weren't well received by the audience, or by Cowell, who looked genuinely offended by the remark. And Howie Mandel didn't seem to agree either.
"When people show up on this show, the level of competition is that much higher. Just by the title, you are amongst Champions," Mandel shared. "Then you show up, and you rip the ceiling off of this theater. You really do. And you know what? That was your fight song, and if I can do anything, I'm gonna help you win this fight!"
Mandel surprised Hale and the other judges by slamming the golden buzzer for the young singer, who was brought to tears as she hugged Mandel amid a rain of golden confetti.
"I can't believe this is actually happening to me," Hale said, through tears of joy. "I mean, I never expected this to happen, and I want to thank you so much!"
ET's Denny Directo caught up with Mandel at the America's Got Talent: The Champions red carpet premiere, and the comedian admitted that having to give out the Golden Buzzer presented some challenges.
"I'm more nervous than hyper critical, because if I'm gonna give someone that Golden Buzzer, I know there's somebody that is also included in Champions coming up next," Mandell explained. "So my concern is if I hit it now did I waste it? Did I have to give it to somebody else who needs it more to the person I gave it to?"
"It's a ton of pressure. I don't know how I do it," he added with a laugh.
America's Got Talent: The Champions airs Mondays at 8 p.m. ET/PT on NBC.