Leona had been the favourite to win Leona's reaction

The 21-year-old from London - the first female to win the ITV show - beat 18-year-old Liverpudlian Ray Quinn.

More than eight million votes were counted during Saturday's final, with Leona receiving 60% of the total.

She will now release a version of the song A Moment Like This, which was first recorded by American Idol winner Kelly Clarkson.

I feel like my dream has come true, the dream I've been dreaming since a little girl has come true Leona Lewis

The single goes on sale in the shops on Wednesday and is tipped among the favourites to secure the Christmas number one.

During the live final Leona was joined on stage by Take That to sing their hit A Million Love Songs, as well as singing Whitney Houston's I Will Always Love You.

'Believe in myself'

After her win, Leona said: "I'm just shocked. It's unbelievable. I feel like my dream has come true, the dream I've been dreaming since a little girl has come true.

"There were points I thought, 'You know what, I don't know if this is going to happen'.

"But with the help from my friends and my family, they all kept telling me to believe in myself and keep on doing it and I did and now I'm here and thank you so much to them."

Ray was joined by Westlife on stage

Liverpudlian Ray sang with Westlife on the cover version of That's Life, and also belted out classics Fly Me to the Moon and My Way.

On Leona's win, mentor and judge Simon Cowell said "he was the proudest person in the world right now".

"Leona has an opportunity, I think, to become a major, major worldwide star," he added.

Thousands of hopefuls entered the competition hoping to make it to the last stages and the chance to sing live in front of millions of viewers.

Last year's winner was Shayne Ward, who went on to have the Christmas number one. The show's first winner, Steve Brookstein, lost his recording contract after falling out of favour with Cowell.