Caly, a 16-year-old aspiring singer from Grand Rapids, OH, stepped onstage in a casual red dress, rocking a pixie haircut.
"My hair wasn't really, like, my choice," Caly told the judging panel after Howie Mandel complimented her look. "I'm a survivor of Stage III ovarian cancer. I kind of came here today to show people that no matter what you've gone through, keep chasing your dreams."
Caly -- who shared photos of herself when she was sick in the hospital, including ones when she was completely bald due to chemotherapy -- sang "Fight Song" by Rachel Platten.
"It was amazing! Your tone and the way that you fell off the note, it was just on point! Couldn't have gone any better for you, I don't think," Mel B said.
"I love everything about you. I just had this feeling when you walked out; I can't explain it. Just your spirit, your choice of song, your voice -- I think you're really special. I've just got this really, incredible feeling about you. I really do," Simon explained. "I think everyone in this room felt it."
Simon predicted that "great things are going to happen" for Caly once she overcomes her nerves onstage.
"Sorry, I've got to do this!" Simon noted as he hit the Golden Buzzer, which will advance Caly straight through to AGT's Season 11 live shows.
Caly cried as Simon walked up onto the stage to hug and congratulate her. Caly's mother was backstage all along tearing up with pride and joy.