Natalie Portman wins Academy Award for Black Swan

American actress Natalie Portman has beaten a list of formidable rivals to win the Best Actress accolade at last weekend's Academy Awards ceremony for her role in ballet thriller Black Swan.

The 29-year-old actress triumphed over Annette Bening, Nicole Kidman, Jennifer Lawrence and Michelle Williams for their roles in The Kids Are All Right, Rabbit Hole, Winter's Bone and Blue Valentine respectively.

Portman had been the favourite for the top prize for her performance as a disturbed ballet dancer in the film, having picked up gongs including a Golden Globe, Screen Actors Guild and Bafta award.

Accepting the accolade, the pregnant star expressed gratitude to her parents, thanking them "first and foremost for giving me my life, and for the opportunity to work at such a young age".

Meanwhile, British actor Christian Bale and American actress Melissa Leo won accolades for their supporting roles in The Fighter, although the latter also became the first Academy Award winner to utter the f-word in an Oscar acceptance speech.