LOS ANGELES, California (CNN) -- In a year when best picture nominees thrived on controversy, the Academy Awards' top honor went to the film that attacked its issues most bluntly.
The Los Angeles social drama "Crash," which interwove plots and characters from different racial and economic backgrounds in Los Angeles, won best picture honors despite favorite "Brokeback Mountain" winning virtually every other major award it had been up for leading up the the 78th Oscars.
The ensemble film, with a cast that included Don Cheadle, Matt Dillon, Sandra Bullock and hip-hop star Ludacris, also won awards for best original screenplay and best editing.
"We are humbled by the other nominees in this category," producer Cathy Schulman said in accepting the Oscar. "You have made this year one of the most breathtaking and stunning maverick years in American cinema."
Haggis was still stunned when he came backstage to talk about the award.
"I didn't believe any of that nonsense," he said of reports that "Crash" was making a late run towards best picture. "We're still trying to figure out if we actually got this."
"Brokeback Mountain" director Ang Lee won best director for his film about the homosexual relationship that grows between two sheepherders in remote Wyoming.
"Brokeback" writers Diana Ossana and Larry McMurtry won the Oscar for best adapted screenplay, and Gustavo Santaolalla took the award for best original score.
The film had been the odds-on favorite for top honors. But "Crash" had strong support for its willingness to address prejudice with its tangled tale of crime and bigotry in the Academy's hometown.
Lee couldn't hide his disappointment backstage.
"I don't know the answer," he said when asked why "Brokeback" didn't end up as best picture. "I was backstage, enjoying the kind of buildup I was familiar with. It was a surprise this year for me."
Philip Seymour Hoffman and Reese Witherspoon were awarded best actor and actress honors.
(actor and atress in leading role)
Hoffman won for his portrayal of Truman Capote in "Capote," while Witherspoon won her Oscar for playing June Carter Cash in the Johnny Cash biography, "Walk the Line."
Backstage, Hoffman -- a versatile actor who has already been pigeonholed with the dread appelation "character actor," usually associated with supporting roles -- said he would continue to choose roles that challenged him.
"I hope all the roles I take are character roles -- lead, supporting, gaffer -- that's how I look at it. I don't look at character roles as supporting roles."
As for why he didn't bark like a dog, which was the subject of a bet about winning Oscar he made years ago, he said it never crossed his mind until he was practically off stage.
"I lost all control over my bowels up there. I thought maybe I'd bark up there for my friends ... but I was swimming in my head," he said. The pressure leading to the award announcement is "not the most comfortable environment."
Joaquin Phoenix, who played Cash in "Walk the Line" was also nominated for best actor.
Rachel Weisz won her first Academy Award for her performance as an impassioned activist who dies under mysterious circumstances in "The Constant Gardener."
And George Clooney won best supporting actor for his performance as a CIA man who starts unraveling the truth in the political thriller "Syriana."
"Wallace & Gromit in the Curse of the Were-Rabbit" was awarded the Oscar for best animated feature film and "King Kong" won for visual effects.
