Gravity-defying Cate Blanchett wins the award...for best supported bust

Actress Cate Blanchett may need to start sharing her beauty secrets.

As the 39-year-old showed off her gravity-defying cleavage at the after party of an awards show in Sydney last night.

Stunning Cate showed off her impressive décolletage in a black velvet corset dress, at at the 2008 Helpmann Awards at Star City Casino.

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Bold front: Actress Cate Blanchett unveiled her impressive decolletage at an awards show in Sydney last night

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Cate Blanchett cuts an impressive figure in her corseted  LBD

The glamorous actress looked slim and svelte in the tight-fitting dress, which she accessorised with a pair of diamante-encrusted Roger Vivier shoes.

But it was her cantilevered cleavage which garned the most attention.

She arrived with her playwright husband Andrew Upton, but he was left firmly in the shade by his glamorous wife of ten years.

The Oscar-winning actress gave birth to her third child in Sydney on April 13th, and revealed that having children was 'addictive'.

She said that the couple can't wait to expand their brood,and that becoming a mother has made her a better person and improved her life considerably.

Cate and her playwright husband Andrew Upton added son Ignatius Martin Upton to their family. They already have two sons: Dashiell John, aged six, and Roman Robert, aged four.

'Having kids is very addictive, if you can, if you're able to and it's your choice and you've got a supportive relationship.'

"You realise how much love you're actually capable of. It's like more doors open in your personality that you didn't even realise were there.

'It's a trip, being a parent, a privilege - even though it means you get a lot less sleep', she said.

Cate recently starred alongside Hollywood star Harrison Ford, 69, as a whip-wielding archaeologist in Indiana Jones and the Kingdom of the Crystal Skull directed by Steven Spielberg.

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I'm with her: Cate Blanchett and very lucky husband of ten years Andrew Upton