Inkabee and Flewnt delivered their most impressive performance to date during the America's Got Talent quarterfinals, but unfortunately the duo did not make it to the next stage.

The dynamic pair took the stage by storm with an exhilarating rendition of their song "Back Again AGT," opening the night and captivating the live audience and with approximately 14 million viewers.

The judges were thoroughly impressed by the father-son team. Howie Mandel was particularly enthusiastic.

"Flewnt and Inkabee, what a way to open a live show, that was amazing. It was so energetic, and I don't know if you could see me and Heidi, but you had us moving like a female Australian breakdancer," he said.

Heidi Klum agreed, praising the coolness and confidence Flewnt and Inkabee displayed, and highlighted the 11-year-old Inkabee as a standout.

Sophia Vergara called their performance spectacular.

"I love you guys, and what I love most is the relationship between the two of you, and how the dad gives the complete spotlight to the kid who deserves it."

However, Simon Cowell offered some surprising advice that left some audience members and judges shocked.

"I think it was very smart doing this together, but I do think there will come a point where you need to separate. If I were your friend, I'd say, 'it might be time to go your own ways.'"

When asked how he felt about Cowell's comments, Flewnt agreed.

"Of course, Inkabee's got his own journey and his own life. I'm here on this world stage for the memories and to help him become the greatest artist he can be. You're right."

Inkabee also shared his thoughts, adding;

"Well, yeah, that's the truth… eventually."

In a previous interview the duo did with Triple J last year, Inkabee said: "My dad has always been a big role model for me and he was my inspiration to become who I am today."

Off-camera FLEWNT got some encouraging words from judge Simon Cowell to take home with him.