Actress Meryl Streep accepts the Oscar for Best Actress for her role in "The Iron Lady" at the 84th Academy Awards in Hollywood, California, February 26, 2012. Photo:Gary Hershorn

Meryl Streep on Sunday won the Oscar for best actress for her scintillating portrayal of former British premier Margaret Thatcher in “The Iron Lady.”

It was the third Oscar for the 62-year-old Streep and her first in three decades, underscoring her status as the pre-eminent actress of her generation.

“Oh, come on!” she said as she was given a standing ovation by the star-studded Hollywood audience.

When her name was called out, she said, “I had this feeling I could hear half of America going, 'Oh no ... her, again',” she added.

Streep defeated a deep field including Viola Davis, who was widely praised for her work in “The Help,” and a cross-dressing Glenn Close in “Albert Nobbs.”

Rooney Mara, who plays damaged hacker Lisbeth Salander in “The Girl with the Dragon Tattoo” was also in the running for the best actress prize, as was Michelle Williams for her turn as Marilyn Monroe in “My Week with Marilyn.” - Sapa-AFP