They will now take on the roles of Danny and Sandy – made famous in 1978 by John Travolta and Olivia Newton John – in a stage production of the hit musical.

Susan and Danny were thrilled to see their dreams come true after beating rivals Michelle Antrobus and Anthony Kavanagh,  in the ITV1 show.

And now Susan, 24, from Dublin, and Danny, 19, from Kent, are set to land massive theatre and record deals.

Simon Cowell, the Grease creator as well as being the Pop Idol and X-Factor presenter,  had already picked Susan and Danny as his favourites before yesterday’s viewers’ vote.

Irish beauty Susan was the red-hot favourite to land her role, but the younger sister of former Westlife star Brian McFadden was determined to ensure she didn’t get favourable treatment. She said: “Obviously because Brian was a big pop star people always associated me with him and thought I was using him to help me get places.

“But that was never the case and I have always thought that I have something to prove.”

The role of Danny was tightly fought between Danny and Anthony – a former pop star who went by the name Kavana and who has high hopes of relaunching his career after the show raised his profile.

Grease will open in London on August 8.