Silent film "The Artist" took home the Best Picture Oscar Sunday night, capping a five-win night that also saw the film's male star and director taking home golden statuettes.
"The Artist" has dominated Hollywood honours this season, winning key prizes at the Golden Globes and awards shows held by the directors, producers and screen actors guilds.
The movie's victory made it the first win for a silent film since the war story "Wings" was named outstanding picture at the inaugural Oscars in 1929.
"I am the happiest director in the world," director Michel Havanavicius said, thanking the cast, crew and canine co-star Uggie. "I also want to thank the financier, the crazy person who put money in the movie."
Before the "The Artist" took home top prize, Meryl Streep was awarded her third Oscar, this time for her performance as former British prime minister Margaret Thatcher in "The Iron Lady."
Streep was sure to thank her husband first, fearing the music would drown her out if she did so at the end of her speech.
"When they called my name, I had this feeling I could hear half of America going, 'Oh no... her again,"' Streep said, to laughs from the crowd. "But whatever."
"I really understand I'll never be up here again. I really want to think all my colleagues, my friends. I look out here and I see my life before my eyes, my old friends, my new friends. Really, this is such a great honour but the thing that counts the most with me is the friendship and the love and the sheer job we've shared making movies together."
Streep -- the record holder with a career total 17 Oscar nominations -- has already won twice.
With Sunday's win, she became the fifth performer to receive three Oscars. Jack Nicholson, Ingrid Bergman and Walter Brennan all earned three, while Katharine Hepburn won four.
Earlier, Jean Dujardin became the first Frenchman to win an Academy Award for best actor, taking the golden statuette for silent film "The Artist."
"I love your country," Dujardin said when he took the stage.
He added: "So many of you here tonight have inspired me."
Dujardin was considered the front-runner after winning the Golden Globe and the Screen Actors Guild awards for his role as a silent-era superstar fallen on hard times in "The Artist."
Before Hazanavicius took home the Best Director Oscar, the film also won Best Score and Best Costume Design.
Plummer wins
Earlier in the evening, Canadian stage and screen legend Christopher Plummer took home Oscar gold for his role in "Beginners."
At 82, the Toronto-born actor, who won Best Supporting Actor, is the oldest actor to win an Academy Award.
Plummer was the front-runner for the award for his role as an elderly widower who reveals he is gay.
"You're only two years older than me darling, where have you been all my life?" he said after receiving his Oscar.
"I have a confession to make. When I first emerged from my mother's womb, I was already rehearsing my Academy thank-you speech. But it was so long ago, mercifully for you I've forgotten it. But I haven't forgotten who to thank."
For this role, he won a Golden Globe, Screen Actors Guild Award, a BAFTA and a Spirit Award. He was previously nominated for his performance in "The Last Station."
Tonight's win marks another high point in Plummer's decades-long career, which includes his star-making role as Capt. Von Trapp in 1965's "The Sound of Music."
Earlier, Octavia Spencer won the Best Supporting Actress Academy award for her role in "The Help."
Spencer was a virtual lock for the Oscar, having dominated earlier film honours for her breakout role as a brash maid in 1960s Mississippi.
A tearful Spencer thanked her family and Steven Spielberg for changing her life.
"Thank you, academy, for putting me with the hottest guy in the room," Spencer said, referring to last year's supporting-actor winner, and this year's presenter, Christian Bale.
Bieber helps Crystal open show
Host Billy Crystal kicked off the 84th Academy Awards riding into the Kodak Theatre on a filmstrip, after being kissed back to life by heartthrob George Clooney and meeting teen pop sensation Justin Bieber in re-enactments of nominated films.
"That was extremely loud and incredibly close," the nine-time host of the Oscars said. He last hosted the show in 2004 and replaced original host Eddie Murphy.
The movies have always been the place to go to laugh, to cry, to text, Crystal joked.
"Nothing can take the sting out of the world's economic problems like watching millionaires present each other with golden statues," he said. Crystal then launched into a musical preview of the best picture nominees, as he did during previous hosting gigs.
Martin Scorsese's Hugo was Oscar night's first big winner taking five production awards. It led going into the awards with 11 nominations, with "The Artist" right behind with ten.
Donning full-length cream-coloured frocks, Jennifer Lopez and Cameron Diaz presented "The Artist" with its first award of the night for costume design.
Toronto-born composer Howard Shore, who already has three Oscars, was beaten for the best score Oscar for "Hugo" by Ludovic Bource for "The Artist."
A number of other Canadians were running in the animated shorts and sound mixing categories.
Iranian film "A Separation" beat out Canadian Philippe Falardeau's movie "Monsieur Lazhar" for best foreign-language Oscar. "A Separation" also won the best foreign film award at the Golden Globes, and it is the first Iranian film to win an Academy Award.
The Academy Awards got a little more Canadian content in the form of Cirque du Soleil, who performed their amazing acrobatics to famous movie scenes. They were introduced by muppets Miss Piggy and Kermit the Frog. The acrobatic extravaganza ended with a standing ovation from the star-studded audience.
The presenters filled the evening with good natured ribbings. Actress Emma Stone poked fun at Ben Stiller in their introduction to the Visual Effects award. Stiller told the "perky" Stone, "you don't want to be the presenter who tries too hard."
Stone retorted that indeed, she didn't want to end up like Stiller, who once presented in full "Avatar" makeup.
"Undefeated" received the Best Documentary Oscar from presenters Robert Downey Jr. and Gwyneth Paltrow. Downey joked that he'd be filming his own doc "The Presenter."
A very animated Chris Rock presented the Johnny Depp vehicle "Rango" with the Best Animated Feature Film award. And the cast of the popular comedy "Bridesmaids" took veiled jabs at all things "short," while presenting the short film Oscars.
"The Descendants" and "Midnight in Paris" picked up the Best Adapted and Best Original Screenplay awards, respectively.
"Descendents" co-screenwriter Alexander Payne, who also directed the film, said his mother demanded that he mention her on stage.
"She made me promise that if I ever won another Oscar I had to dedicate it to her just like Javier Bardem did with his Oscar. So mom, this one's for you," he said. "Thank you for letting me skip nursery school so we could go to the movies."
Woody Allen, who won the screenwriting Oscar for his critically acclaimed film "Midnight in Paris," skipped the ceremony. He holds the Oscar record for writing nominations with 15.
With files from The Associated Press
