The small-budget British film — shot in the teeming slums of Mumbai — was named best picture as widely predicted and won seven other Oscars.
At the climax of the night, the stage was swarmed by jubilant members of the Slumdog cast and crew, including several school children who were plucked from Mumbai’s shantytowns to appear in the movie.
British filmmaker Danny Boyle was named best director for the often dark but ultimately hopeful tale of a young orphan who risks it all for love and a shot at instant wealth as a TV game show contestant.
“It is a love story but is heavily disguised,” he said. “The spine appears to be the game show but … there’s another story underneath, which is the love story,”
Adding to the international flavour of this year’s Oscars, hosted by Australian stage and film star Hugh Jackman, three of the night’s four acting awards went to non-Americans.
Kate Winslet of Britain was named best actress for her dramatic turn as a former Nazi prison guard who has a love affair with a teenage boy in The Reader.
Penelope Cruz broke through as the first Spanish actress to claim an Academy Award, winning for her supporting role in the Woody Allen romance Vicky Cristina Barcelona.
And Australian Heath Ledger, who died last year of an accidental prescription pill overdose, was named best supporting actor for his role as the evil Joker in the Batman blockbuster The Dark Knight. He became only the second performer after Peter Finch to win an Oscar posthumously.
Sean Penn, the lone American among the newly honored performers, was voted best actor for his portrait of slain gay rights leader Harvey Milk in the political drama Milk.
But Slumdog was the big winner. Besides best picture and best director, the film also earned Oscars for cinematography, sound mixing, film editing, original score and song.
Shot on a modest budget of $15 million, the film was orphaned at one point when it was dropped by financier Warner Independent Pictures, a division of Warner Bros. Fox Searchlight Pictures ultimately rescued the film and released it in November.
It went on to win raves from critics and crossed over from arthouse success to delight mainstream audiences, grossing nearly $100 million domestically to date.
The movie’s triumph restored a kind of feel-good mood to the Oscars amid the global economic downturn, following several years in which dark dramas, No Country for Old Men, The Departed and Crash topped the Oscars.
The only arena in which the film was overshadowed was in the acting categories, where A-list stars earned the nominations over the relatively unknown cast of Slumdog.
Winslet, a six-time nominee, fought back tears when accepting her trophy and remembered a time as a child when she dreamed of winning it.
“I would be lying if I said I haven’t made a version of this speech before. I think I was probably 8-years-old and staring into the bathroom mirror,” she said.
Penn, who won an Oscar five years ago for his performance as a grieving father in Mystic River, used his acceptance speech for Milk to condemn passage of California’s recent ballot measure banning gay marriage as a “great shame.”
The film’s Oscar-winning screenwriter, Dustin Lance Black, a gay Mormon, struck a similar chord in his remarks from the stage, telling young gays and lesbian viewers, “…You are beautiful, wonderful creatures of value.”
The night’s biggest surprise came in the foreign-language film contest, with Japan’s funereal drama Departures upsetting Israel’s animated anti-war film Waltz With Bashir.
Despite Oscar producers’ hopes of rejuvenating the ceremony, early reviews of the show were largely negative.
The Los Angeles Times said Jackman “never radiated any real heat,” and the Washington Post opined that his opening medley of songs lampooning the best picture nominees was “pointless and flat for all Jackman’s workmanlike efforts to enliven it.”