The show's four judges - Simon Cowell, Heidi Klum, Mel B and Mandel - each praised the humble Guardino following his rendition of the classic The Jackson 5 song. "There's something about you, and it's just the best possible feeling when we meet someone like you", he said.
Howie asked Guardino, "If you could make one wish right now, what would it be?" His performance left the always opinionated Simon Cowell speechless, while fellow judge Howie Mandel granted Guardino's wish for the golden buzzer, meaning the contestant automatically advances to the next round.
When you get a double thumbs-up from Cowell, you know you've done something right.
The performance was preceded by a segment in which Guardino and his mother, Elizabeth, described how the teen went from being blind for most of his life due to a retinal disease called Leber congenital amaurosis until he was cured thanks to an experimental gene therapy that allows him to see.
Auditions for Season 12 of America's Got Talent rolled on Tuesday night.
"Well your wish just came true", answered Mandel, standing up to reach across the table and hit the Golden Buzzer.