The 9-year-old had everyone talking after calling Amanda a "dog" during his audition, and on his return in the semi-finals he roasted the judges once more.
Walking up to the judges' desk during the week's live heats, Ned said: "Amanda, after last time, I'm trying to come up with some nice things to say about you.
"So please help me get to the final, because I'm going to need a lot more time!"
Ned's jokes saw him make it into the top two of the public vote, winning a spot in the final this weekend.
Tonight saw Ned's final performance and this time he let the judges off lightly, but some other celebs didn't escape Ned's "savage" quips.
"How scary were those clowns last night? I haven't seen wacky costumes and terrifying make up like that since Sharon Osbourne as a judge," he said.
Ned went on: "You've got to love shows like Britain's Got Talent and The X Factor, where else do you get to see tedious singing robot? Gary Barlow!"
The remark drew claps from Simon Cowell as he sat on the panel.
After the performance, the judges were full of praise for Ned, with Simon commenting: "I've got a feeling in about ten years' time you might be sitting in this chair instead of me!"
Resident comic David Walliams said: "That was an incredibly confident performance from anyone, let alone someone four days in to their 9th birthday."
Amanda Holden added: "I would never have pressed my buzzer! Although it was savage, it was much cleverer than your audition."
Britain's Got Talent 2017 airs on ITV.