The unassuming mother-of-two brings back memories of Susan Boyle, who stunned viewers with her powerful voice on ITV's Britain's Got Talent in 2009.
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The judges as well as Xtra Factor presenters Caroline Flack and Matt Richardson hinted that Sam was one contestant to watch for.
"Sam Bailey blew me away," said Nicole, speaking at an X Factor event. "Daaayyyuummm! Sam Bailey can sing!! Who else wasn't expecting THAT voice?!? #onetowatch #XFactor," she later tweeted.
"There's a brilliant 'Over' this year," added Caroline, without naming names. "She's got that shock factor. I suppose not SuBo but she's got that, 'you don't know she's going to be that good' thing about her."
"Hey guys haven't tweeted off here for a while how is every one, wasn't Sam Bailey amazing- Jaymi xx," wrote last year's contestants Union J after Saturday's episode.
Sixteen-year-old Tamera Foster, who was split up from her singing partner Jerrie in the small room auditions, was another contestant that the Xtra Factor co-host hinted she had been backing from the start.
"There's one girl who I've championed since day one and she's still in," said Caroline. "I think she's going to win. She's the best singer I've ever heard. She's in the 'Girls' category."
While Caroline could not reveal names, she seems to have been referring to Tamera who impressed the judges in her first audition. Originally part of the duo act Silver Rock, Tamera went on to win the nation over at the live arena auditions with her rendition of Whitney Houston's I Have Nothing.
The trendy songstress looked and sounded every bit the pop singer but her nerves got the better of her when she started performing and forgot her lines. Asking to have a minute, Tamera went backstage and composed herself, and came back with more passion and confidence to the cheers of crowds.
The other half of her duo act, 22-year-old Jerrie, meanwhile, did not make it past live auditions.