In their last chance to impress the judges before The X Factor Grand Final, the top four took to the stage last night to prove they have what it takes to win.

The theme was Killer Tracks and Curveballs which saw them performing two tracks - one mega hit plus a song to show they can tackle anything. Some acts flourished while others stumbled.

The night belonged to Cyrus who unleashed a side never seen before, rapping to Ed Sheeran's Don't. "It would be a joke if you're not in the Grand Final," James Blunt said. And he knocked his Curve Ball - Phil Collins' In The Air Tonight - out of the park. "I've got the Cyrus Virus," Dannii Minogue said. "That was a Grand Final performance. You have to be there."

It was a return to form for Big T who nailed the recent hit Marvin Gaye. "That's my favourite performance of yours to date," Guy Sebastian said. And he didn't come unstuck singing his Curveball track, A Whiter Shade of Pale. "You are back!" Dannii declared.

No stranger to Curve Balls, Jess & Matt rose to the challenge of KISS' I Was Made for Lovin' You. "You are the ones to beat," Dannii said. But the other judges were critical of Guy's song choice with James calling it a "Curveball too far". Chris Isaak added: "I don't think the vocals, tambourine and acoustic guitar went with this song."

But the Sydney lovebirds bounced back with Lady Antebellum's Need You Now, a song fans have been calling for them to sing all season. "You really make it look easy," Dannii said, complimenting their effortless harmonies.

Louise Adams' Killer Track Ain't No Sunshine didn't fire the way her mentor James had hoped and he was quick to blame himself. "It was rather uninspired as a song choice. I feel like I've let you down." The Mount Gambier mum leapt to his defence saying, "James works so hard with me every week."

After admitting to giving Louise "intense, miserable, moody" songs this series, James chose a happy track Blame It On Me by George Ezra as her Curve Ball. While Dannii said she enjoyed seeing her smile, the other judges weren't convinced. "You didn't seem comfortable to me tonight," Chris said.

Which three acts will earn a place in next week's Grand Final? Don't miss tonight’s show at 7.30pm when the Grand Finalists are revealed. Matchbox Twenty front man Rob Thomas will sing along with Justice Crew, plus Guy Sebastian, who will perform his brand new single.