The Ballyfermot woman blew the judges and audience away again this week with her rendition of “Could it be Magic” by Bary Manilow.
The 50-year-old Tesco check out worker had been under pressure from judges to diversify her song choice and show more variety.
However it was sad news for the other Dublin contestant Rebecca Creighton and her girl band Belle Amis who were voted off last nights show. The group have vowed to stay together.
Meanwhile “X Factor”sources have revealed that Byrne has been guaranteed a two album record deal by Simon Cowell whether she wins or loses the show.
A source close to Mary revealed: "The album deal has already been done, no matter what happens. She doesn't need to worry about money ever again thanks to her incredible performances on the show.
"Mary can't believe her luck. She went in to the audition hoping to make it on to the show - but she never believed in her wildest dreams she'd be such a big hit.
"Simon is determined to sign her to his record label and has already pencilled her into his release schedule for next year. She'll be guaranteed at least a million in the next 12 months -- and there's also talk of a tour, promotions and a number of endorsement deals.
"Tesco are also extremely keen to sign her up and pay her €100,000 for a TV ad campaign as soon as she is finished on the show.
"This is all new territory for Mary and she already has a personal advisor, appointed by the X Factor, to start negotiating deals on her behalf," the source added.
Looks like there is a very bright future in store for this Irish contestant!