Sinners star Michael B Jordan won best actor and the film's cinematographer Autumn Durald Arkapaw made Oscar history as the first female director of photography to win the award.
Australian hopefuls Rose Byrne and Jacob Elordi both missed out on Academy Awards, with Byrne overtaken in the best actress contest by Jessie Buckley and Elordi beaten by Sean Penn for best supporting actor.
Nick Cave was also overlooked for an Oscar, with the title track to the film Train Dreams losing out to Golden from KPop Demon Hunters for the original song award.
The favourite coming in, One Battle After Another won six Oscars, including best director and best adapted screenplay for Anderson, the event's first trophy for best casting, and best supporting actor for an absent Penn.
"I wrote this movie for my kids to say sorry for the housekeeping mess that we left in this world - we're handing off to them," said Anderson while accepting the screenplay trophy in Los Angeles on Sunday night, US time.
"But also with the encouragement that they will be the generation that hopefully brings us some common sense and decency."
Sinners, which came in with a record 16 nominations, landed four wins, including best original screenplay as well as best actor for Jordan in one of the night's closest races.
Buckley won best actress for her performance as Agnes Shakespeare in Hamnet, making her the first Irish performer to ever win in the category.
"It's Mother's Day in the UK," said Buckley on the stage. "I would like to dedicate this to the beautiful chaos of a mother's heart."
As expected, the Netflix sensation KPop Demon Hunters, 2025's most-watched film, won best animated feature, as well as best song for Golden.
"This is for Korea and Koreans everywhere," said co-director Maggie Kang.
Another Netflix release, Guillermo del Toro's Frankenstein, picked up three awards for its lavish craft, for costume design, makeup and hairstyling and for production design.
Amy Madigan won best supporting actress for her performance in the horror thriller Weapons, a win that came 40 years after the 75-year-old actor was first nominated, in 1986, for Twice in a Lifetime.
Hosting for the second time, Conan O'Brien hit a number of targets, like Timothee Chalamet for his diss of opera and ballet, but also struck a serious note, alluding to "chaotic and frightening times".
But he argued that the current geopolitical climate made the Oscars all the more resonant as a globally unifying force.
"We pay tribute tonight, not just to film, but to the ideals of global artistry, collaboration, patience, resilience and that rarest of qualities today - optimism," O'Brien said.
Security was tight in and around the ceremony. Organisers said they were working closely with the FBI and Los Angeles police after a federal warning of a possible Iranian threat against California, though authorities cited no specific or credible danger to the Academy Awards.
Mr Nobody Against Putin, a film about a Russian primary school teacher who documents his students' indoctrination to support Russia's war with Ukraine, won best documentary.
Elegy also marked the Oscars. Producers expanded the in memoriam segment following a year that featured the deaths of so many Hollywood legends, including Diane Keaton, Robert Duvall and Robert Redford.
Barbra Streisand spoke of Redford, saying "Bob had real backbone", and sung a few bars of The Way We Were.
Billy Crystal paid tribute to Rob and Michele Reiner, who were killed in their home in December, quoting 1987's The Princess Bride.
"All we can say is: Buddy, how much fun we had storming the castle," said Crystal.
with Reuters
