Ant McPartlin thought X would win Britain's Got Talent 2019 after the mystery magician's shock identity reveal stunned the judges and hosts.
Singing Chelsea pensioner Colin Thackery was crowned champion of the ITV talent contest's thirteenth series in tonight's live final.
However, the most talked-about moment came when the person behind X was finally unmasked as former BGT semi-finalist Marc Spelmann.
While appearing as X, the trickster concealed his identity by wearing a plain white face mask and using eerie pre-recorded narration.
But Marc revealed himself during his finale performance, which saw him time-travel back to his original BGT audition last year.
The moment shocked the judges, who insist they had absolutely no idea about X's real identity.
"I personally thought it was a girl," Simon Cowell claimed afterwards on ITV2 spin-off Britain's Got More Talent.
"None of us, honest to God, knew what was coming."
David Walliams commented: "I thought he created an amazing moment in the show by revealing himself.
"It kind of made us all think, 'yeah, he really deserved another chance', because this guy is a clever, clever performer."
No-one was as dumbfounded as presenters Ant and Dec.
The duo pressed the Golden Buzzer for Marc last year, and unwittingly featured in all of his performances as X.
Ant reckoned Marc's stunt was so captivating that he would 'pip' Colin to victory.
"That was a proper special TV moment that, crowning Colin," he said. "I thought from when we saw the audition go out, he's got a very good chance of winning.
"Then the whole X reveal on tonight's show, I thought he'd pipped it."
Dec added: "It's the fact he was our Golden Buzzer from last series! We've been doing stuff, he'd been electrocuting us, I didn't have a clue!"
Meanwhile, the Geordie favourites rubbished More Talent frontman Stephen Mulhern's suggestion that Marc may have stood a better chance had he kept the secret.
"The reveal was the moment, because that was the whole trick," Ant commented."Going back not only to the audition of this year, but to his very first audition."
"I'm not sure we would have got as good a moment if he hadn't revealed himself," agreed Dec.
It was confirmed tonight that Britain's Got Talent will be back on ITV later this year for an all-star 'Champions' edition.