Cillian Murphy, Robert Downey Jr and director Christopher Nolan were all honoured for their work on Oppenheimer as the film dominated the Bafta Awards.
Murphy was named best actor for playing J Robert Oppenheimer, known as the father of the atomic bomb, while Downey Jr won best supporting actor.
The drama won seven Baftas including best film. Poor Things picked up five, including best actress for Emma Stone.
Best supporting actress went to Da'Vine Joy Randolph for The Holdovers.
Oppenheimer and the acting winners could well repeat their successes at the Oscars in three weeks - although Oscar and Bafta voters rarely totally agree.
In a surprise appearance, Michael J Fox announced Oppenheimer as the winner of best film, the top prize at Sunday's ceremony. The 62-year-old, who has had Parkinson's disease for more than 30 years, received a standing ovation from the audience.
Murphy told the ceremony after winning the first Bafta of his career: "Oh boy. Holy moly. Thank you very, very much Bafta."
The Irish actor paid tribute to his "Oppenhomies" and praised Nolan, adding: "Thank you for always pushing me and demanding excellence because that is what you deliver time and time again."