Hadwin shocked the judges (and the audience) with her surprisingly powerful take on Otis Redding's "Hard to Handle" on Tuesday night. "And then you sing, and you're like a lion", Cowell marveled.
"Genuinely incredible", said Simon. "You're from a whole different era", said Howie Mandel. "Oh my gosh! You are not from this era".
Hadwin openly wept with joy as the golden confetti rained down from the rafters, and was embraced in a big hug by her proud father, who had been watching his daughter perform from the wings of the stage.
When the music started, the 13-year-old transformed into a mini Janis Joplin. I don't know if you've ever seen the documentary but Clive Davis goes to the Monterey Pop Festival and he sees this young girl that nobody has ever seen before, that nobody knows.
She first went viral when a video of her singing at her school lunchtime open mic session got loads of views on YouTube. "I'm not Clive Davis. The only thing I can do for you, young lady, is give you..."
The show first aired on NBC on Tuesday, May 29 and in the run up, Courtney could be seen on the advertising trailer.
In 2018, she was a finalist on The Voice Kids UK, airing on ITV in the United Kingtom.