South Korean black comedy Parasite has made history by winning the Oscar for best picture - the first non-English language film to score the coveted award.
The South Korean film about a poor South Korean family infiltrating a wealthy household, beat strong competition from films including the heavily-favoured war epic 1917 to take home its fourth statuette of the night.
Earlier, it won the prizes for best director for Bong Joon-ho, best international feature and best original screenplay to become the big winner on Hollywood's biggest night.
"I thought I was done for the day and ready to relax," Bong said upon winning best director honors, before promising to "drink until next morning."
"We never write to represent our countries," Bong said earlier in the night when he took the screenplay award. "But this is (the) very first Oscar to South Korea. Thank you."
Bong also paid tribute to his childhood hero and fellow nominee Martin Scorsese, drawing a standing ovation for the veteran director of The Irishman.
Australia's Margot Robbie misses out
Meanwhile, Joaquin Phoenix won best actor for Joker and Renee Zellweger collected best actress for Judy.
Australia's Margot Robbie was an early casualty.
Robbie was nominated in the best supporting actress category for Bombshell but the trophy went to Laura Dern for Marriage Story.
Aussie Margot Robbie missed out on an award. Source: EPA
Dern was the red-hot favourite for what is her first Oscar win after coming up empty-handed in 2015 for Wild and 1992 for Rambling Rose.
It also ended a drought for her famous family, with her mother Diane Ladd nominated three times without a win and father Bruce Dern also falling short despite two nominations.
"I share this with my acting heroes, my legends, Diane Ladd and Bruce Dern," she said on stage.
"You got game."
New Zealand's Taika Waititi claimed the beating fellow Kiwi Anthony McCarten (The Two Popes), Greta Gerwig (Little Women), Todd Phillips and Scott Silver (Joker) and Steven Zaillian (The Irishman).
Hollywood veteran Brad Pitt won best supporting actor for his performance as a charming stunt man in Once Upon a Time in Hollywood, director Quentin Tarantino's love letter to 1960s Tinseltown.
New Zealand director Taika Waititi poses in the press room with the Oscar for Best Adapted Screenplay for 'Jojo Rabbit'. Source: AFP
It was the first acting Oscar for Pitt, 56, after three decades in the movie industry.
He previously won an Academy Award as a producer in 2014 for best picture 12 Years a Slave.
In his acceptance speech Pitt called out the Trump impeachment trial for blocking the testimony of former national security adviser John Bolton.
"They told me I only have 45 seconds up here, which is 45 seconds more than the Senate gave John Bolton this week," he said on stage.
Toy Story 4 won best animated feature.
Elton John and Bernie Taupin won original song for Rocketman's (I'm Gonna) Love Me Again.
John immediately called his sons who are in Australia.
"I just Face Timed them," John told reporters backstage.
Additional reporting by AAP and AFP
