Morgan Freeman opened the 84th Academy Awards before host Billy Crystal appeared in a spoof showreel based on scenes from nominated films including The Descendants, The Help and The Artist.
Tom Hanks presented the first awards of the night for cinematography and art direction to Martin Scorsese's Hugo.
Next up were Cameron Diaz and Jennifer Lopez to present the awards for costume design to The Artist. They also presented the award for make-up to the team behind The Iron Lady. The next award, for foreign-language film, went to the Iranian film A Separation.
Christian Bale handed out the award for supporting actress to Octavia Spencer for The Help. The tearful actress, who was given a standing ovation, thanked her family in Los Angeles and Alabama before wrapping up, saying "I'm freaking out".
The Oscar for film editing was given to The Girl With The Dragon Tattoo. The award for sound editing went to Hugo as did the Oscar for sound mixing.
Gwyneth Paltrow joined Robert Downey Jr on stage to present the Oscar for best documentary to Undefeated. The award for animated feature film went to Rango, while the gong for visual effects was presented to the team who worked on Hugo.
The supporting actor award went to Christopher Plummer for Beginners. The 82-year-old, the oldest actor ever to win an Oscar, held up his statuette and said: "You're only two years older than me darling, where have you been all my life?"
The award for original score went to Ludovic Bource for The Artist, while the gong for original song went to Bret McKenzie for his song Man Or Muppet from the latest Muppets film. Angelina Jolie presented the award for adapted screenplay to The Descendants. The award for original screenplay went to Woody Allen for Midnight In Paris.
The award for Best Director went to Michel Hazanavicius for The Artist, and his leading actor Jean Dujardin was named Best Actor. The French star told the audience "I love your country" and thanked swashbuckling screen idol Douglas Fairbanks Jr for inspiring his role.
The best actress Oscar was presented by Colin Firth to Meryl Streep whom he described as "unreasonably good". Mission Impossible star Tom Cruise presented the best picture Oscar to The Artist - the first silent film to win in decades. Producer Thomas Langmann accepted the award as he was joined on stage by the cast and crew including Uggie the dog.