The X Factor USA frontrunners Alex & Sierra joined forces with the UK show's most successful export Leona Lewis last night for a brilliant duet.
The star collaborations have become a fixture of X Factor finals on both sides of the Atlantic, and last night Simon Cowell's last remaining group took to the stage with to perform the hitmaker's most successful song, 'Bleeding Love'.
Leona said afterwards: "It's been so awesome, they're so cool and lovely, and we were having nice chats backstage.
Alex and Sierra could win tonight (WENN)
"Like, seriously, nice genuine people. Thank you for having me."
However, judge Demi Lovato was critical of the sing-song, telling the pair once Leona had left the stage: "I felt like, to be honest, it wasn't your best performance. Obviously Leona killed it, she outshined you a bit." But the eliminated mentor added: "I still think you have what it takes to win the competition."
Cowell gushed: "You respected the artist. I thought it was a beautiful version. Leona Lewis changed this show forever and I believe you can change this show forever as well."
Also last night, Jeff Gutt performed with the frontman of the Goo Goo Dolls to sing 'Iris', and Carlito Olivero sang 'Stand By Me' with Prince Royce.
The winner will be crowned tonight (December 19).