"Most of the audience was laughing, but when I opened my mouth that seemed to change," Boyle said in a pre-taped package ahead of her performance, reflecting on her famous debut performance. "You don't expect people to get that excited about you."
"Britain's Got Talent absolutely changed my life," she continued. "People saw me as somebody quite ordinary. I lived alone with my cat, Pebbles. [Now], I've sold 20-million records! Wow, even I'm overwhelmed. This has helped me fulfill the dream I've had since I was five."
Boyle has spent a great deal of the money she's earned through her record sales on charities and philanthropic endeavors, and has become a role model for so many people with big dreams, which is why she felt it was right to return to Champions.
"I think I'm a champion for maybe those who don't have the confidence to do things, for those who don't have a voice and for those who people tend to ignore," she shared. "I feel I'm a champion for them."
The love for Boyle was evident from the moment she took the stage, as the audience burst into cheering and revelry, much to the singer's delight and appreciation.
"Susan, I mean genuinely, I'm beyond thrilled that you're here tonight," Cowell shared before she sang.
"I'm happy to be here," Boyle said with a smile. "It's great to be in America."
Showing her true vocal range and musical mastery, Boyle wowed the audience with a heartwarming, beautiful rendition of The Rolling Stones' "Wild Horses," and it was every bit as flawless as fans were expecting.
"I can't think of any other contestant who had defined this show better than you," Cowell shared after the breathtaking number. "You've made a huge difference to a lot of people's lives, and I'm so happy you're here."
"I just want to say what an absolute honor and a pleasure it is to be sitting here listening to you, and your angelic voice," Mel B shared. "I want to be the woman that gives you something that you deserve."
The Spice Girls star sent the crowd into a frenzy of excitement as she stood up and slammed the Golden Buzzer for the celebrated songstress, sending Boyle into the finals for America's Got Talent: The Champions.
Boyle was brought to tears as Mel B and host Terry Crews embraced her on stage, where they were joined by Cowell, who couldn't have been more excited for the talented star.
As Crews asked the emotional singer how it felt to get the Golden Buzzer, a choked up Boyle said sweetly, "I'm happy and very humbled. Thank you so much."