Chloe Zhao has made history as the second woman to win a best director Oscar.
The filmmaker, who is the first woman of colour to win the award, was recognised for her road movie Nomadland, about a woman travelling through the American West.
The only other woman to win the directing prize is Kathryn Bigelow, who was honoured for The Hurt Locker in 2010.
Accepting the prize, the Chinese filmmaker recalled a game she would play with her father, where they would recite classic Chinese poems and texts.
She cited one as her favourite, offering the English translation as “people at birth are entirely good”.
Zhao said: “Even though sometimes it might seem like the opposite is true, but I have always found goodness in the people I have met everywhere I went in the world.
“So this is for anyone who had the faith and the courage to hold on to the goodness in themselves and hold on to the goodness in each other, no matter how difficult it is to do that.
“This is for you, you inspired me to keep going.”
Daniel Kaluuya, who was born in London to Ugandan parents, is the first black British winner of the best supporting actor prize, as he was celebrated for his portrayal of Black Panther leader Fred Hampton in Judas And The Black Messiah.
In his acceptance speech, Kaluuya told of his admiration for Hampton, who was shot and killed by police in Chicago in 1969 when he was 21.
He praised Hampton’s work in the black community and took aim at the forces of the state that worked to bring him down.
“When they played divide and conquer, we say unite and ascend,” Kaluuya said.
Addressing the star-studded audience, Kaluuya said: “There’s so much work to do guys and that’s on everyone in this room.
“This ain’t no single man job.
“We’ve got work to do.
“I’m going to get back to work Tuesday morning, because tonight I’m going out.”
Kaluuya, speaking with his mother in the audience, added: “My mum met my dad, they had sex, it’s amazing. I’m here.
“I’m so happy to be alive so I’m going to celebrate that tonight.”
British filmmaker Emerald Fennell won best original screenplay for her directorial debut Promising Young Woman and fought back tears as she delivered her improvised acceptance speech.
Looking at her statuette, she said: “He’s so heavy and he’s so cold.”
She paid tribute to the cast and crew, who made the film over a 23-day shoot.
Fennell, who was pregnant during the shoot, joked she was crossing her legs during production.
Christopher Hampton and Florian Zeller won the prize for best adapted screenplay for their work on the agonising drama The Father.
In his acceptance speech, Zeller, who appeared via video link from his native France, paid tribute to the film’s star, Sir Anthony Hopkins, and described him as the greatest living actor.
Best international film was won by Danish movie Another Round.
Oscars producers had said they wanted the broadcast to resemble a film and the opening stuck to that theme.
Regina King’s walk through the historic Union Station in Los Angeles was captured in a cinematic tracking shot, before she opened the show with a defiant monologue.
King said while many watching at home may reach for their TV remotes when celebrities start talking politics, as a black woman and mother to a black son, race was not an issue she could ignore.
She said had the verdict in the Derek Chauvin case gone another way, she would have put on her marching boots.
King outlined the rigorous safety measures in place for the in-person ceremony, including vaccinations, tests and social distancing.
Attendees were not required to wear masks on camera but were asked to cover their faces when not on screen.
Attendance was limited to 170 people, with audience members rotated in and out during the ceremony.
The ceremony finally took place after a two-month delay and a bruising year for the film industry, with cinemas around the world closed for months on end and productions disrupted.
Promising Young Woman star Carey Mulligan, Pieces Of A Woman actress Vanessa Kirby and The Father’s Olivia Colman are all nominated for prizes at the ceremony.
Sir Anthony, Sound Of Metal’s Riz Ahmed, Mank’s Gary Oldman and The Trial Of The Chicago 7’s Sacha Baron Cohen are also in the running.
There was no host and instead the Academy relied on a cast of star-studded presenters.