who won best picture

The Hurt Locker, the gritty Iraq War drama about an Army bomb disposal squad, won best picture and nabbed an Oscar for Kathryn Bigelow, the first woman to win best director. She's the ex-spouse of fellow director nominee James Cameron, whose blockbuster Avatar was tied with Hurt Locker with a field-leading nine nominations but won just three statues. Hurt Locker wound up with six.

"This really is ... there's no other way to describe it, it's the moment of a lifetime,'' said Bigelow, 58. "I'd just like to dedicate this to the women and men who risk their lives on a daily basis in Iraq and Afghanistan and around the world, and may they come home safe."

Jeff Bridges won best actor for his portrayal of an alcoholic country singer in Crazy Heart. Sandra Bullock won best actress for portraying a nurturing mom in the feel-good football drama The Blind Side.

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"Whew! Thank you Mom and Dad ... they loved showbiz so much," said Bridges. "This is as much honoring them as me."

Said Bullock: "Did I really earn this or did I really just wear y'all down?"

Their wins, which many critics had predicted, did little to overshadow the drama surrounding the two nominations leaders. Box office king Avatar, which has pulled in nearly $2.6 billion worldwide to date, picked up early Oscars for cinematography, art direction and visual effects but was shut out of top categories. Locker ($21.3 million to date) won for sound editing, sound mixing, film editing and original screenplay early on. The screenplay statue was accepted by Mark Boal, whose work was based on his experience as an embedded journalist with the Army in Baghdad.

"I would like to thank and dedicate this to the troops," Boal said. "The 115,000 still in Iraq. The 120,000 in Afghanistan, and the more than 30,000 wounded and 4,000 who have not made it home, and to my father, who did not live to see this. He died a month ago."

Both Bridges and Bullock had picked up Golden Globes and SAG awards this season. Perhaps best known for his role as The Dude in 1998's The Big Lebowski, Bridges, the son of the late actors Lloyd Bridges and Dorothy Dean Bridges, had been nominated five times.

Oscars watchers believed Bullock's main competition was Meryl Streep, nominated a 16th time for Julie and Julia.

Brassy, sassy Mo'Nique, best known for her TV comedic skills, won the best-supporting-actress Oscar for her dramatic role in Precious: Based on the Novel 'Push' by Sapphire.

The stand-up comic and TV talk show host, 42, acknowledged Hattie McDaniel— the first African-American to win an Oscar, for 1939's Gone With the Wind— and thanked supporters including Tyler Perry, Oprah Winfrey and the academy, "for showing that it can be about the performance and not the politics."

Precious' Geoffrey Fletcher won for best adapted screenplay.

Austrian-born Christoph Waltz won best supporting actor for his work in Quentin Tarantino's Inglourious Basterds, the first major category winner Sunday.

"Quentin, with his unorthodox methods of navigation, took this ship across and brought it in with flying colors," said Waltz, 53. "This is your welcoming embrace, and I can never thank you enough, but I can start right now."

Among other winners, Ryan Bingham and T Bone Burnett won best song for their Crazy Heart theme, The Weary Kind, while Pixar's computer-animated Up won for best animated feature. The best animated short film Oscar went to Logorama.

Basterds was Waltz's first major Hollywood film. But the veteran European actor's win was hardly surprising — he'd already swept most major acting awards for his role as a duplicitous Nazi officer in Tarantino's World War II drama about Jewish-American soldiers spreading fear in Nazi-occupied France.

Earlier on the red carpet, Mo'Nique said she hoped Precious' bleak but ultimately uplifting story would be inspirational.

"It's changed my life inwardly, and we're hoping the message of this movie changes lives," she said. "And when that happens, everything is different, because people are healing."