Olly Murs & Demi Lovato Go 'Up' on 'X Factor UK' Final - Watch Now!

Demi Lovato and Olly Murs light up the stage at the 2014 X Factor UK Finals in London, England on Sunday night (December 14).

The two musicians brought the crowd to their feet with their new duet, “Up”.

PHOTOS: Check out the latest pics of Demi Lovato

“Just finished doing @TheXFactor with this beauty!” Olly captioned with a cute snap of the duo on Twitter.

Before their performance, Olly and Demi got in a big Christmas sweater with One Direction‘s Niall Horan and Sam Smith.

Watch their performance below!