It was a good night for X Factor contestant Cher Lloyd on Saturday, after she gave what Simon Cowell described as “the performance of the series”.

The 17-year-old landed the plaudits on the show’s Halloween themed week after she swapped her usual hip-hop image for a long black dress to sing the Shakespear’s Sister chart-topper Stay.

And while she was overcome by emotion at the end of the song, the judges were quick to reassure her.

“That wasn’t just the performance of the night,” Simon Cowell told her afterwards, “it was the performance of the entire season.

“I think you are special, you proved a point this week. You’re only 17 years old and that performance, by any standards, was absolutely incredible.”

Louis was also quick to praise the teenager. “I don’t know why you’re crying,” he said, “tonight you proved that you’re not just a one-trick pony and you really can sing.”

Front-runners Mary Byrne and Rebecca Ferguson also fared well, Mary sporting devil’s horns to sing the Barry Manilow hit Could It Be Magic, and Rebecca wowing the panel with her rendition of Chris Isaak‘s Wicked Game.

“Last week I liked you, this week I loved you,” Simon said of Mary, while Dannii Minogue called her a “class act”.

Simon was also full of praise for Rebecca. “You’re beginning to remind me of when Leona Lewis was on this show and I saw somebody who week after week was turning into a star,” he said. “Great, great choice of song.”

And it was another good week for Katie Waissel, who looked almost unrecognisable under silver eye make-up and a huge head of hair as she sang the Ella Fitzgerald song Bewitched.

“You were born to be on the stage and be a performer,” Louis Walsh told her, “you’re different.”

Simon, meanwhile, said she looked like a “singing scarecrow” but added, “I think this competition would be a more boring place without you.”

Also faring well were the two remaining bands, One Direction and Belle Amie, Treyc Cohen, who attempted to avoid another brush with the bottom two with her performance of Relight My Fire, and Paije Richardson, who dressed in a suit jacket and red bow tie to sing Amy Winehouse‘s Back to Black.

“You have got it all,” Louis Walsh told him, “you are getting better and better.”

Meanwhile favourite Matt Cardle took on another challenging song in the shape of Leona Lewis’ Bleeding Love – and some of the judges expressed their doubts. “I loved the vocals,” Louis said, “but I wasn’t keen on the song.”

However Simon disagreed. “I liked that it wasn’t a copycat version, that it wasn’t karaoke. It was a smart choice of song and I think there’s no question that you’re going to be here next week.”

However Aiden Grimshaw’s pared-down version of Michael Jackson‘s Thriller divided opinion amongst the judges. Simon called the performance “bizarre” and “indulgent” while Cheryl said, “I’d like to see you smile a bit more. Not every song requires that intensity.”

And Wagner also failed to impress the panel with another medley which blended the operatic song O Fortuna with Meat Loaf‘s Bat Out Of Hell.

Dannii called the performance “unusual” but Simon was a little more blunt. “What the hell was that?” he asked. “Louis, what are you drinking? I didn’t understand a single word.

“Having said that,” he added, “people like you and if they vote for you I can always leave the country.”

The results will be revealed on Sunday evening’s show with one more act eliminated from the competition.