First-time winners Lupita Nyong'o and Jared Leto took supporting acting honors, while the 3-D spectacle "Gravity" amassed a force of technical awards in an Oscar ceremony punctuated by politics, pizza and photo-bombing.
Wearing Nairobi blue, the 31-year-old Nyong'o, breakout star of the historical drama "12 Years a Slave," accepted the award for best supporting actress. In her feature film debut, Nyong'o made an indelible impression as the tortured slave Patsy.
"It doesn't escape me for one moment that so much joy in my life is thanks to so much pain in someone else's, and so I want to salute the spirit of Patsy for her guidance," said Nyong'o. She also thanked director Steve McQueen: "I'm certain that the dead are standing about you and they are watching and they are grateful, and so am I."
Two hours into the Dolby Theatre ceremony, hosted nimbly by Ellen DeGeneres, Alfonso Cuaron's box-office hit and visual marvel had accrued five Oscars, winning for cinematography, editing, visual effects, sound mixing and sound editing. If the Mexican Cuaron wins best director, as he's expected to, he'll be the first Latino filmmaker to take the category.
As expected, Leto won for his acclaimed, gaunt performance as a theatrical transgender suffering from AIDS in the Texas drama. He thanked his mother, his date on the night.
"Thank you for teaching me to dream," said Leto. Later backstage, he passed around his Oscar to members of the press, urging them to "fondle" it. The actor, who had devoted himself in recent years to his rock band 30 Seconds to Mars, gravely vowed: "I will revel tonight."
Sunday's Oscars hung on a nail-biter of a finish, with the best picture race believed to be between the historical drama "12 Years a Slave," the 3-D space spectacle "Gravity" and the con-artist comedy "American Hustle." DeGeneres alluded to the options in her opening monologue.
"Possibility number one: '12 Years a Slave' wins best picture," she said. "Possibility number two: You're all racists."
Her opening went over well in Los Angeles' Dolby Theatre, which had far more mixed reactions to last year's "We Saw Your Boobs"-singing host, Seth MacFarlane. She chided Leto ("Boy, is he pretty") and mocked Jennifer Lawrence for falling on her way onto the red carpet, just as she did when she accepted the Oscar last year for "Silver Linings Playbook."
When Lawrence hit the carpet and waved to fans, she collapsed in a heap of laughter.
"If you win tonight, I think we should bring you the Oscar," said DeGeneres to Lawrence, nominated for her performance in "American Hustle."
Though the ceremony lacked a big opening number, it had a musical beat to it. To a standing ovation, Bono and U2 performed an acoustic version of "Ordinary Love," their Oscar-nominated song from "Mandela: Long Walk to Freedom," a tune penned in tribute to the late South African leader Nelson Mandela. Singing his nominated "Happy" from "Despicable Me 2," Pharrell Williams had Meryl Streep and Leonardo DiCaprio dancing in the aisles. Pink was cheered for her rendition of "Somewhere Over the Rainbow," part of a 75th anniversary tribute to "The Wizard of Oz."
Best documentary went to the crowd-pleasing backup singer ode "20 Feet From Stardom." One of its stars, Darlene Love, accepted the award singing the gospel tune "His Eye Is on the Sparrow": "I sing because I'm happy/ I sing because I'm free."
Disney's global hit "Frozen" won best animated film, marking - somewhat remarkably - the studio's first win in the 14 years of the best animated feature category. (Pixar, which Disney owns, has regularly dominated.) With box-office that recently passed $1 billion globally, the film was sure to be the biggest hit to take home an Oscar on Sunday.
"We're all just trying to make films that touch people," said co-director Chris Buck backstage. "Once in a while, you get lucky."
Though the Oscar ceremony is usually a glitzy bubble separate from real-world happenings, international events were immediately referenced. In his acceptance speech, Leto addressed people in Ukraine and Venezuela.
"We are here and as you struggle to make your dreams happen, to live the impossible, we're thinking of you," said Leto.
Russian state-owned broadcaster Channel One Russia said it would not broadcast the Oscars live because of the necessity for news coverage of Russia's invasion of Ukraine's Crimea peninsula. It will instead transmit the Oscars early Tuesday morning, local time.
Venezuelan protesters, via social media, urged Oscar winners to bring attention to their plight. Anti-government protests have roiled the country in recent weeks.
Italy's "The Great Beauty" won the Oscar for best foreign language film. In accepting the award for his rumination on life and Rome's decadence, director Paolo Sorrentino thanked his heroes, including Federico Fellini, Martin Scorsese and soccer star Diego Maradona.
DeGeneres gently mocked Hollywood's insularity, referring to the headlines that have swamped the Los Angeles area lately with a slightly less serious news event.
"It has been raining," said DeGeneres. "We're fine. Thank you for your prayers."
The talk-show host quickly circulated in the audience, delivering pizza and appealing to Harvey Weinstein to pitch in on the bill. She also crowded in as many stars as she could in hopes of generating the most-tweeted photo ever. Meryl Streep giddily exclaimed: "I've never tweeted before!" In less than an hour, the resulting image had been retweeted more than 880,000 times.
Other early winners included "The Great Gatsby" for best costume design, and best makeup and hairstyling for the low-budget "Dallas Buyers Club."
ABC, which is telecasting the ceremony, hopes the drama of the best-picture race will be enough to entice viewers. The show last year drew an audience of 40.3 million, up from 39.3 million the year before when the silent-film ode "The Artist" won best picture.