The 25-year-old singer performed a mash-up of songs on last night's show, including Take That's 'Back for Good' and Psy's 'Gangnam Style'.
When Clark discovered that he had escaped the bottom two this week, he repeatedly jumped up and down before picking up his mentor Nicole Scherzinger and carrying her across the stage.
Speaking to presenters Caroline Flack and Olly Murs on The Xtra Factor, Scherzinger said that ahead of his performance, Clark was "so excited". She continued: "Bless his heart... He's been practicing all day."
Wearing a T-shirt with 'Leave the Boy Alone' written on the front, Clark said he "can't get my head around" being voted to stay in the competition. He added: "Can I just say honestly thank you so much [to the public] for voting for me. Means the world to me. I promise I will bring it next week."
Flack exclusively revealed on The Xtra Factor that next week's song theme on the show is 'Club Classics'.
The X Factor continues next Saturday (October 20) at 8.20pm on ITV1.
Photo gallery - The X Factor second results show:
Copyright: Ken McKay/Thames/Rex Features