SOUTH Korean film Parasite became the first non-English-language movie to win the best picture Oscar, in a significant upset for British war film 1917.
The class satire by auteur Bong Joon-ho also won best director, best original screenplay and best international feature, leaving Sir Sam Mendes empty-handed.
It was widely thought that the British filmmaker would win his second directing Oscar for the First World War epic, filmed to appear as one long take.
It would have come exactly 20 years after his win for American Beauty but he was pipped to the post for the Academy Award by director Bong, despite success at both the Baftas and the Golden Globes.
The South Korean filmmaker appeared stunned to win the directing prize, saying: "After winning best international feature, I thought I was done for the day and ready to relax."
He quoted Martin Scorsese, saying: "When I was young and studying cinema, there was a saying that I carved deep into my heart, 'What is the most personal is the most creative'," and asked the audience to stand in honour of the veteran director.
1917 did enjoy success in the cinematography category, where Roger Deakins won his second Oscar in three years.
It was also celebrated for sound mixing and visual effects.
In the acting categories, there was success for Joaquin Phoenix, Renee Zellweger, Laura Dern and Brad Pitt, while Sir Elton John triumphed in the original song category.
He won alongside his long-time collaborator Bernie Taupin for their track (I'm Gonna) Love Me Again for biopic Rocketman.
Pitt won his first acting Oscar for his supporting role in Once Upon A Time... In Hollywood and took a swipe at the Senate and thanked his children.
He previously won a best picture Oscar as the producer of 12 Years A Slave, but this is his first acting prize.
Dern won the best supporting actress Oscar for her role in Marriage Story.
"Some say never meet your heroes but I say, if you're really blessed, you get them as your parents," she said.
"I share this with my acting legends, Diane Ladd and Bruce Dern. You got game, I love you."
Ladd was nominated for the best supporting actress prize three times but never won.
Phoenix won the leading actor prize for Joker and used his impassioned speech to talk about equality rights.
He said: "I think at times we feel or are made to feel that we champion different causes. But for me, I see commonality. I think, whether we're talking about gender inequality or racism or queer rights or indigenous rights or animal rights, we're talking about the fight against injustice."
Phoenix became tearful at the end of the speech as he remembered his late brother, the actor River Phoenix, who died aged 23 in 1993.
He said: "When he was 17, my brother wrote this lyric, 'Run to the rescue with love and peace will follow'."
Zellweger paid tribute to Judy Garland as she was named best actress for her role as the Wizard Of Oz star in Judy.
She said: "And though Judy Garland did not receive this honour in her time, I am certain that this moment is an extension of the celebration of her legacy that began on our film set and is also representative of the fact that her legacy of unique exceptionalism and inclusivity and generosity of spirit.
"Miss Garland, you are certainly among the heroes who unite and define us and this is certainly for you. I'm so grateful."
The Oscars ceremony, which did not have a host for the second year in a row, featured a surprise appearance from Eminem.
The rapper performed his Oscar-winning song Lose Yourself, 17 years after he snubbed the ceremony.
