The blind and autistic 22-year-old left the audience stunned with a soul-wrenching rendition of Calum Scotts You Are The Reason.
Your story is unbelievable. But now lets take it back to your talent. Every time you come on, particularly tonight, you put your twist on a song that makes you, in my opinion, one of the most special, talented contestants, Simon said after Kodi received a standing ovation.
The crowd was so moved they were chanting the performers name by the end of the song.
Gabrielle Union, who joined the Americas Got Talent team this season, said: We are all so grateful to be in your orbit.
Kodis performance is just one of the 11 acts being performed during the semi-finals, with only five lucky acts moving on to the finals.
Will & Graces Sean Hayes could barely keep himself together during Lees act, admitting he had tears in his eyes.
Kodi was noticed globally after his performance of Donny Hathaways A Song For You during his audition earned him the golden buzzer, which meant he was so good that he got to skip the contest and move straight to the semi-finals.
Watch it yourselves below, its astonishing:
Both times, the judges – especially the 59-year-old music mogul Simon – were completely entranced by the performance.
Americas Got Talent fans noticed something very special about Kodis semi-final song that made it that much more special.
One eagle-eyed viewers commented on YouTube: Omg this was the same song that played during his golden buzzer moment.
Wow, thats a great observation! another AGT fan wrote in reply.
It will be a tough decision on who goes to the final, as Kodi had to go up against some tough competition including impressionist Greg Mortion, the Ndlovu Youth Choir and singer Ansley Burns.
The final will be airs in the US on 17 and 18 September and streams on Netflix in the UK.