Simon Cowell was pelted with eggs by a former contestant who has a bitter vendetta against him for not putting her through the auditions in a previous series.
Police were called to the Britain’s Got Talent studio on Saturday night after the violinist, who was part of opera act Richard and Adam’s orchestra, threw eggs at the judge.
Natalie Holt, wearing a black dress, ran through the stage, in between the brothers, and began throwing eggs at Cowell. She smiled as she continued to chuck the packet at him.
Following the brothers' performance, Ant and Dec said: "We'd just like to point out that was not part of the performance. Well done for carrying on."
Shocked Simon, 53, had to go backstage to change his shirt, while security guards marched the brunette girl out.
The music mogul said of the attack: “I told Sinitta the other day that I don’t like eggs and I really don’t like eggs, I’m sorry for you guys.
“I thought she was throwing a sandwich at me.”
Amanda Holden spoke positively about the performance and branded the egg thrower a "stupid girl" as she gave her comments during the show.
Cowell went outside for a cigarette and was comforted by a female friend afterwards.
Simon Cowell gets egged on the Britain's Got Talent final
Amanda Holden, who sits next to Simon and narrowly missed out on being attacked, let out a gasp as Alesha Dixon and David Walliams looked on in horror.
A young girl sitting behind the judges table had to change her clothes while Jack Carroll made light of the situation when he took to the stage.
Fans of the show took to Twitter to speak out about the egg throwing.
One user wrote: "Can't wait till we find out who 'Egg Girl' is on Twitter. Bet she thinks she's some hero when really she's made herself look a right wench."
Another posted: "LOOOOL! why an earth did a lady on Britain's Got Talent throw egg's on the judges while people were performing; the way she got dragged off!"
Comedian contestant Jack Carroll made light of the incident and opened his performance with a joke about eggs.
He said: “My first joke I was going to run and throw some eggs but that’s been ruined.”
Following his performance, Simon said: "Only you could open with a joke about eggs. Absolutely brilliant."
Egg-thrower Natalie later apologised.
Britain's Got Talent 2013 finalists