Philippine soap star Jaclyn Jose won best actress at the Cannes film festival Sunday for her mesmerising performance as a slum matriarch who falls prey to corrupt police.

A huge star in her homeland, she said she had to forget everything she learned in her 30 years in the business for the role as a sweetshop owner and small-time drug dealer in "Ma' Rosa".

"The biggest challenge for me was not to act. Especially since I am coming from television shows where I play loud and campy characters," she told reporters.

The 52-year-old said she had to "tone everything down to zero" -- for the stark, realistic portrait of a woman fighting to do the best for her family in director Brillante Mendoza's gritty film.

It is a dramatic change from her regular job, playing a spoilt, rich woman in the popular Philippine TV soap opera, "The Millionaire's Wife".

Variety magazine praised Jose for the "naturalistic grace" of her film performance, playing the matriarch of a family struggling to survive amid squalor.

The daughter of a Filipina mother and a largely absent American serviceman father, Jose first became famous in Philippine showbiz circles for her ethereal beauty. 
But she has proved to be a versatile and hard-working actress, starring in dramas, comedies, horror stories, romances as well as television soap operas.

She has won numerous acting awards in her native country and worked with its most prestigious filmmakers.

But it is her relationship with "Ma 'Rosa" director Mendoza -- a friend for over three decades -- which has brought her into the international limelight.

She appeared in Mendoza's first movie "The Masseur" 11 years ago and also his drama "Serbis", which competed in Cannes in 2008.