LOS ANGELES (Reuters) - Jennifer Lawrence won her first Oscar on Sunday for her lead role as an outspoken young widow in the quirky comedy "Silver Linings Playbook."
Lawrence, 22, an early front-runner for the prize, fended off strong competition from Jessica Chastain and 86-year old French actress Emmanuelle Riva for the Best Actress prize.
"You guys are just standing up because you feel bad that I fell down," Lawrence said, as the Dolby Theatre audience rose to its feet after she tripped on her way up the stairs to the stage where she accepted the award.
"But thank you," she added, clutching the statue. "This is nuts."
Asked backstage what was going through her mind as she stumbled, falling on her hands, Lawrence responded: "A bad word that I can't say that starts with 'F'."
Lawrence became the second youngest winner of the award, according to the Academy. The youngest is Marlee Matlin, who won in 1987 for "Children of a Lesser God" at the age of 21.
In "Silver Linings," Lawrence plays a young woman who becomes a sex addict after the death of her husband, and then strikes up an unlikely romance with a bi-polar former teacher played by Bradley Cooper.
The role proved the versatility of the young actress, whose film work has ranged from independent dramas to big budget action fare like "X-Men: First Class" and "The Hunger Games," in which she plays heroine Katniss Everdeen.
Lawrence also won Golden Globe and Screen Actor's Guild awards ahead of Sunday's Oscars, usually predictors of the Academy Award.
In recent weeks, some Oscar experts detected a groundswell of support for Riva after the "Amour" star, who turned 86 on Oscar Sunday, won at the BAFTA awards earlier this month in England.
Lawrence won her first Oscar nomination for her break-out performance as a teen trying to keep her dysfunctional family together in the 2010 independent film "Winter's Bone."
Asked if she worried that her career might be peaking too soon, Lawrence quipped: "Well, now I am."
Backstage, she joked with reporters about the stress of Oscar night.
"I'm just cross-eyed," she said. "The process today was so stressful I felt like Steve Martin from 'Father of the Bride,' watching my whole house being torn apart."
Producers of "Silver Linings Playbook" initially felt Lawrence was too young to play the feisty widow, but she struck up an endearing chemistry with Cooper's character, Pat.
One of the busiest actors in Hollywood, Lawrence finished shooting on "The Hunger Games: Catching Fire," scheduled for release in November, according to the movie site IMDB.
She and Bradley Cooper, her "Silver Linings Playbook" co-star, will be reunited in "Serena," a Depression-era movie that is scheduled to be released in September.
Next year, she is scheduled to appear in the six installment of the X-Men series, "X-Men: Days of Future Past."
Lawrence was born in Louisville, Kentucky, and started her career at the age of 14 with small roles in film, television and in commercials.
She soon moved with her family to Los Angeles where acting jobs came steadily and in 2010 she was named one of Variety magazine's Top Ten Actors to Watch.
Lawrence's swift rise to the top has made her a hot commodity in the fashion world and celebrity magazines, where she regularly turns heads on the red carpet.
In December she was named the world's "most desirable woman" by website AskMen after rising from the No. 47 spot a year earlier.
She is a regular face on the front covers of magazines like Vogue, and in October she became the new face of Christian Dior's Miss Dior brand of handbags.
Additional reporting by Ron Grover; Editing by Mary Milliken and Sandra Maler