Kate Winslet won a Leading Actress film Bafta for The Reader, as Slumdog Millionaire cleaned up at the awards with seven gongs including Best Film.
The night of British triumphs saw Danny Boyle win the Director prize for Slumdog Millionaire, the rags-to-riches tale set in the slums of Mumbai.
Slumdog has already taken Hollywood by storm and is poised for Oscar success, having received 10 nominations.
The Orange British Academy Film Awards, one of the most glamorous events in the film calendar, saw A-listers including Brad Pitt, Angelina Jolie, Sharon Stone, Penelope Cruz, Daniel Craig, Ron Howard and Michael Sheen brave the downpour to dazzle on the red carpet.
Appearing breathless, Winslet said in her acceptance speech: "Okay! Thank you very, very much. To be given this award at home, this really means a great deal to me.
"Thank you Bafta, thank you. I want to thank everybody involved in the making of this film. They all know who they are and they all deserve a big fat piece of this. I want to thank my friends and my family, especially my mum and dad, who I will not look at right now, otherwise I will burst into tears. Thank you mum and dad so much for your love and support."
Winslet, who plays a concentration camp guard in The Reader, beat Jolie for Changeling, Kristin Scott Thomas for I've Loved You So Long and Meryl Streep for Doubt. She also faced stiff competition from herself - having also been nominated in the category for her role in Revolutionary Road, which reunited her with Titanic co-star Leonardo DiCaprio.
Frost/Nixon, which received six nominations and centres around Sir David Frost's verbal jousting with disgraced former US president Richard Nixon, failed to pick up a single gong. Changeling, which had eight nods, also left empty handed.
Eyes were also on the ceremony's host Jonathan Ross, fresh from his suspension over the Andrew Sachs lewd phone calls row, though it was Mickey Rourke who turned the air blue, saying he had been "f****** up my career for 15 years".
Rourke was named Leading Actor for his comeback role in The Wrestler, beating Dev Patel for Slumdog, Brad Pitt for The Curious Case of Benjamin Button, Sean Penn for Milk and Frank Langella for Frost/Nixon.
