Alex and Sierra had a rough week on “The X Factor USA” (TXFU) Top 12 finalists performance show on Episode 16. But as they took the stage on Top 10 performance show on Episode 18, the real-life couple turned the table around and owned the night.

The America’s sweethearts impressed the judges with their cover of One Direction’s “Best Song Ever,” on Nov. 20 performance night dubbed, “British Invasion.”

Kelly Rowland loved it while Demi Lovato proclaimed it’s the couple’s best performance of the season as of yet.

“I think you guys should be really proud of yourselves,” Rowland said, according to Entertainmentwise.com.

Lovato can’t wait to go home and download the song on iTunes.

“I think this was your best performance yet,” Lovato began, said Entertainmentwise.com, before adding, “I’m actually gonna go home and download [your song] on iTunes tonight because I love that so much."

Simon Cowell has found confidence again in his group. Alex and Sierra has Cowell as their mentor in Group acts and the British mogul did not hold back when he said he was a bit disappointed with the couple’s rendition of “Addicted to Love” by Robert Palmer last week.

But Alex and Sierra kept their promise last week that they will make Simon proud of them again.

Simon said, "You carry on like this, guys, you have a serious chance of winning this show."

Watch Alex and Sierra perform One Direction’s “Best Song Ever” on Nov. 20, performance night on Fox’s “The X Factor USA.”

VIDEO Credit: YouTube/The X Factor USA

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