The Hurt Locker emerged on top at the Academy Awards Sunday night, winning best picture and making history, as Kathryn Bigelow became the first woman to win an Oscar for direction.

"This really is, there is no other way to describe it, the moment of a lifetime," Bigelow said as she took the stage at Hollywood's Kodak Theatre to accept her landmark trophy as best director.

Bigelow, whose film had faced ex-husband James Cameron's blockbuster Avatar in nine categories, paid tribute to her fellow nominees.

"It's so extraordinary to be in the company of my fellow nominees, powerful filmmakers who have inspired me and who I have admired, some for decades."

She also dedicated the win to "the women and men in the military who risk their lives on a daily basis in Iraq and Afghanistan and around the world. Come home safe."

'This really is, there is no other way to describe it, the moment of a lifetime.'—Kathryn Bigelow

The Hurt Locker, which focuses on the life-and-death pressures facing a close-knit bomb squad stationed in Iraq, also picked up trophies for sound editing, sound mixing, film editing and its original screenplay by Mark Boal, who said he came up with the story after covering the Iraq War as a journalist.

"We had this fantasy of making our film, our way, with the talent we hoped to have," Boal said on stage, as he was surrounded by the film's cast and creative team.

"To be standing here, this was truly never part of our wildest dream."

The Hurt Locker and Avatar had started out Oscar night as rivals with the most nominations. However, Canadian filmmaker Cameron's 3-D extravaganza — the most successful film ever at the box office — nabbed prizes largely for its stunning imagery: best art direction, cinematography and visual effects.

First-time wins for actors

Hollywood veteran Jeff Bridges finally had his Oscar moment Sunday night, winning his first Academy Award for an acclaimed turn as a hard-living country singer seeking redemption in Crazy Heart. His received his first nomination in 1971 for The Last Picture Show.

"Whoa!" Bridges declared in response to receiving a standing ovation, before moving on to honour his performer parents, Lloyd and Dorothy Dean Bridges, who encouraged him and his siblings to follow in their footsteps.

"Thank you mom and dad for turning me on to such a groovy profession," he said. "They loved show biz so much, I feel an extension of them. This is honouring them as much as me."

Sandra Bullock, dubbed America's Sweetheart for her numerous roles in box-office friendly romantic comedies, picked up her first-ever nomination and Oscar for The Blind Side, in which she has a rare dramatic turn playing a wealthy southern woman who adopts a homeless teen and helps turn him into a football star.

"Did I really earn this or did I just wear you all down?" Bullock quipped in a speech that honoured her fellow nominees and was at times sentimental, but also punctuated by jokes.

"I would like to thank — what this film was to me — the moms who take care of all the babies in the world, no matter where they come from," she said, later also recalling her mother, the late German opera singer Helga Bullock.

Bullock's win was also one for the history books, as she became the first performer to win both an Academy Award and the dubious Golden Raspberry prize on the same weekend. Her triumph at the Oscars came a night after she turned up to accept the worst actress Razzie for the box-office flop All About Steve — with a wagon full of the film's DVDs.

A pair who have been unanimously recognized for landmark performances capped their film season trophy hauls with best supporting actor Oscars: Christoph Waltz, for Inglourious Basterds, and Mo'Nique, for Precious: Based on the Novel Push by Sapphire.

Waltz, a familiar face from European stage and television, picked up the evening's first trophy for his turn as a villainous Nazi in Quentin Tarantino's film — his first Hollywood role. Waltz thanked the American director for taking his career in a new direction.

"Quentin, with his unorthodox methods of navigation, this fearless explorer, took this ship across and brought it in with flying colours, and that's why I'm here," Waltz said.

"This is your welcoming embrace and there's no way I can ever thank you enough, but I can start now. Thank you."

Mo'Nique, an actress, comedienne and talk show host best known for brash, low-brow humour, delivered a startling, widely acclaimed performance as a monstrous single mother in Precious.

"I would like to thank the academy for showing it can be about the performance and not the politics," she said as she took the stage.

Mo'Nique also paid tribute to Hattie McDaniel, the Gone With the Wind actress who was the first black performer to win an Oscar, Precious' executive producers Tyler Perry and Oprah Winfrey, and to her husband, Sidney Hicks, "for showing me that … you have to forgo doing what's popular to do what's right and, baby, you were so right."

Multiple wins

Precious was among the evening's double winners, with Geoffrey Fletcher nabbing the urban drama's second Academy Award for his script adaptation of poet Sapphire's story.

"This is for everybody who works on a dream every day," he said, his voice wavering. "To Precious boys and girls everywhere."

Along with the end-of-evening best actor trophy for Bridges, Crazy Heart won one of the night's early prizes when Ryan Bingham and T Bone Burnett were honoured for the film's theme song, The Weary Kind.

Also scoring two Oscars was adventure tale Up, winner of the best animated feature Oscar and best original score. It is the third consecutive Pixar film to win the Academy Award for animated feature.

"Never did I dream that making a flip-book out of my third-grade math book would lead to this," said director Pete Docter.

One of the evening's upsets was in the foreign-language film category, with Argentina's The Secret in Their Eyes (El Secreto de Sus Ojos) taking the title over higher-profile entries that have dominated other award shows, included Germany's The White Ribbon and France's A Prophet.

The 82nd annual Academy Awards, which opened with a song-and-dance number by Neil Patrick Harris and playful ribbing of this year's nominees by hosts Steve Martin and Alec Baldwin, also took a few breaks for tributes.

In addition to a dance segment set to the best score nominees and video montages paying homage to Hollywood's horror films, honorary Oscar-winners Lauren Bacall and Roger Corman and the annual tally of industry figures who have passed away, organizers put together a tender, stand-alone homage to John Hughes, with actors from some of his biggest films speaking as part of a tribute to the late U.S. producer, director and screenwriter.

Molly Ringwald, Matthew Broderick, Ally Sheedy and Macaulay Culkin were among those who spoke about Hughes — who died in August 2009 — as a montage of his many teen and family comedy-dramas rolled on screens behind them, including Ferris Bueller's Day Off, The Breakfast Club, Some Kind of Wonderful, Home Alone, Weird Science and Planes, Trains and Automobiles.

With files from The Associated Press