By Matthew Green

CANNES, France (Reuters) - Bjork proved at Cannes that even after one film she has mastered the first rule of acting -- how to leave the audience hungry.

The Icelandic pop icon stole the show when she scooped the Golden Palm award on Sunday for best actress in her film debut in the weepy melodrama "Dancer in the Dark.''

But adoring applause from the film festival crowd turned to bewilderment when the elfin singer said her acting career was over as soon as it had started.

"I knew when I said yes that this would be my first and last role,'' the raven-haired sensation told a news conference.

"After three months of shooting, I was feeling like a fish out of water -- It was too much in the world of words and not enough in the world of music,'' she said.

Bjork enchanted audiences with her portrayal of a Czech immigrant in the rural 1960s America, saving her meager wages to pay for an operation to prevent her son from inheriting a disease that is slowly making her blind.

Danish director Lars von Trier originally approached her to write the score for the film, that bursts into colorful musical moments dreamed up by her character, but she was eventually persuaded to take the lead part.

The movie won the Golden Palm for the best film, but Bjork said that when she had watched the Cannes premiere she was more interested in hearing how the soundtrack she wrote had turned out than watching her own performance.

"For me, the only thing that matters is the music -- I have no ambitions on the acting. I wish I could have cared about the film, but I'm not an acting person,'' she said.

Music will always remain the meaning of life for the woman who grew up in a hippie commune of artists and musicians, but the thrill of winning the Golden Palm was not lost on her.

"I was having a big rush at that moment, I was tripping-- my heart beat at the moment went from about 60 beats per minute to 120 beats,'' she said.

Bjork, who recorded her first solo album at the age of 11 and founded an all-girl punk group called "Spit and Snot'' when she was 15, said she found her magic in the recording studio and not on the screen.

"The film was very, very painful to do and all my records have been joyful,'' she said.

"I'm very happy -- It feels like my journey is complete,'' she said.