The NBC reality competition series wasted no time bringing out the legendary Rock band to the stage, as they opened the show and helped host Tyra Banks welcome judges Howie Mandel, Heidi Klum, Mel B and Simon Cowell.
The opening performance brought a mixture of responses from fans of the reality series, with some complimenting their skills after all these years.
"KISS is definitely more my speed than whatever the opening act was last week," one Twitter user said during the performance.
"I am getting to introduce my 16-year-old son to KISS! This is so fun!" another user said of the epic moment.
"The members of KISS maybe a little over the hill, but it's still fun to see them. A guilty pleasure," another added.
Not everyone was a fan of the performance, however, with some users even accusing the iconic band of lip syncing during the performance.
"Kiss really? I would rather watch a mime," one user mused.
"Did KISS really just open [America's Got Talent Finale]?" asked another, adding the wondering face and a no signal emoji.
At the end of their performance, Banks asked the band about their upcoming farewell tour, The End of the Road World Tour.
"This is going to be our last tour, so explosive, biggest show we've ever done, people who love us come see us, if you've never seen the show come see us," the band teased at the end of their performance.
The band's official site is also teasing the End Of The Road World Tour, with more details to be announced soon.
For this live finale, ten individuals with diverse talents will be giving final performances before the winner of the $1 million prize is announced before the end of the show.
With the competition as close as ever before, Cowell said close to the end of Tuesday's finale performances: "Of all the finals, this is the most open... I think some of you tonight are going to have life-changing moments."
America's Got Talent is expected to return for a 14th season in 2019. Spinoff series America's Got Talent: The Champions will reportedly premiere during the 2018-2019 TV season.