A few weeks ago Rietta Austin was singing to a handful of drinkers in a south London pub.

Then came a call asking if she'd like to perform in front of an audience closer to 12,000 - and make history by doing so.

Tomorrow, Austin will become the first headline act at the new-look Dome, four days before Bon Jovi officially opens the O2 arena.

The former dance teacher, who moved to London from New Zealand eight years ago, will perform at a "community day" organised by the venue's owners to ensure there are no hitches or health and safety problems for the Sunday night opening.

"It really will be a dream come true for me," said the 36-year-old. "I still can't quite believe I'll be up there in front of all those people tomorrow night. This is everything I came to London for."

Having made her performing debut aged three alongside her jazz-singer mother, Austin trained in dance in Los Angeles and appeared in Cats and Jesus Christ Superstar in New Zealand and Australia before moving to London.

"I knew no one and my first gig was a karaoke contest in the East End that I found through an ad in The Stage," she said. "But I won it and met some musicians through that and since then it's gone from strength to strength."

In recent years Austin has been a fixture on the pub and club circuit. She was asked to headline the Dome by Tony Moore, music promoter at The Bedford, the Balham pub where Paolo Nutini, James Morrison and Imogen Heap started out.

Mr Moore said: "Rietta is an amazing artist who the wider public don't know yet, but by the end of the night I am sure she will have won thousands of fans. She's got such a great stage presence; to my mind she has always been an arena artist, even when she's performing in front of 200 people in a pub."

Austin's recently sang backing vocals for Shirley Bassey's next single, a cover of the Pink hit Get The Party Started.

She said: "Shirley Bassey is one of my idols, but nothing can compare to the feeling I'll have when I get up on stage tomorrow night."

Bon Jovi will earn more than £1million for their show but Austin is being paid just £750, which she plans to give to her eight-piece band. "It's only fair because they have done lots of gigs with me for nothing," she said.