In a unique race, 22-year-old Jennifer Lawrence defeated the oldest and youngest Oscar nominees to take home the Best Actress Oscar for her role of a recovering sex addict in David O Russell's Silver Linings Playbook.

The actress, who established herself as a box office superstar with The Hunger Games franchise, won the Oscar voters' affection with her grabby, comedic and very quirky character of Tiffany, a young widow in a shaky new relationship with a man fresh from a mental hospital.

"This is embarrassing... It is nuts...thank you to the Academy, to the women this year. Thank you to the best production team, our crew and my family... Thank you so much," said Lawrence as she accepted her trophy. The actress had a embarrassing moment as she fell down while climbing the stairs to accept her trophy.

She beat off competition from 86-year-old Emmanuelle Riva (Amour), nine-year-old Quvenzhane Wallis (Beasts of the Southern Wild), Jessica Chastain (Zero Dark Thirty) and Naomi Watts (The Impossible).

Lawrence started her career from TV sitcom The Bill Engvall Show and in barely six years, the actress has risen from a relatively unknown to superstardom. Her Oscar winning Lawrence is more known for her independent movies The Burning Plain (2008) and Winter's Bone (2010), for which she was nominated for an Academy Award.

Silver Linings Playbook centers on the relationship between a man (Bradley Cooper) just out of a mental hospital and a young widow (Lawrence).

The film is also up for best picture and director David O Russell is nominated for adapted screenplay and director category. Cooper is in the running for the lead-acting honors. The movie also has Indian actor Anupam Kher in a small but significant role.

Lawrence recently claimed the Golden Globe and the Screen Actors Guild honor for her role.