Matt Cardle showed he's still got a spark by singing a rousing version of Katy Perry's Firework.
The pop hopeful, who's been battling a throat infection, donned some bright yellow trousers and a black shirt to belt out the tune.
He was flanked by an orchestra of female violin players, and dancers in wacky blue costumes.
All four judges gave him a standing ovation.
Louis Walsh told him he'd "paid [his] dues in the music business" by playing so many gigs in the past.
He added: "You're consistent, your versatile, you've got a great recording voice, Dannii you've done a brilliant job, you could win the show."
Cheryl Cole, who still has Rebecca Ferguson in the show, surprisingly told Matt: "It would be lovely to see you crowned winner so best of luck."
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Simon Cowell - often derided for his own choice of trousers - took issue with Matt's outfit, saying: "Apart from the trousers I thought it was absolutely fantastic, great choice of song."
Matt's mentor Dannii Minogue defended herself against criticism she had given Matt too many girls' songs to sing.
She said: "A sensational vocal, whatever anyone says about me giving you too many girls songs, I dare any other guy to sing all those female song you have this series, phenomenal, thank you."
Matt said it was an "honour" to be in the final, adding: "There's no real words to describe how it feels to be here."
