X Factor boss Simon Cowell hinted at the backstage tension between mentor Cheryl Cole and her acts on Saturday's live show with barbed comments aimed at the Geordie singer.
Cole flew to the US this week to sign her own record deal with Universal and returned to reports of jealous in-fighting between her four remaining acts, Cher Lloyd, Katie Waissel, Rebecca Ferguson and Treyc Cohen.
And after 17-year-old Cher opened the ITV show with rapper Jay-Z's Empire State Of Mind, unimpressed Cowell blamed Cole for the teenager's "copycat" performance.
He said: "Last week was 100% original. This was a little bit copycat and I'm not blaming you. All I'm saying is that, with the standard of the competition this year, to make the final, knowing what is coming up, you've got to be more original and therefore I think your mentor got a little bit lazy tonight."
He also told Treyc that Cole had to give her a "killer instinct" to win the competition.
Treyc gave a confident rendition of Aerosmith's I Don't Want To Miss A Thing, after which Dannii Minogue said the singer had "that sparkle back".
But Cowell said: "It's like if you have a lion, you want it to bite you, not lick you. That's what you're missing at the moment, it's that killer instinct that you can win. What you're missing is passion and you have to believe in yourself and Madame (Cole) has to give it to you."
But it was painter and decorator Matt Cardle who stole the show with an emotional version of The First Time Ever I Saw Your Face by Ewan MacColl, made famous by Roberta Flack. The 27-year-old, from Essex, received a standing ovation from all four judges, with Cole describing his performance as "spine-tingling".
The 10 acts will have to wait until Sunday night to find out who will be leaving the competition.