Daniel Day-Lewis has won best actor for his role in There Will Be Blood by the Los Angeles Film Critics Association.
Daniel Day-Lewis plays a petroleum baron in the film
The oil boom epic set in the early 1900s was also named best film, with a third award for best production design.
French star Marion Cotillard scooped best actress for her role as singer Edith Piaf in La Vie En Rose.
The critics' awards come ahead of the Golden Globe nominations on Thursday, which can boost the Oscar chances of lesser known films.
Romanian film Four Weeks, Three Months and Two Days won two awards - for best foreign language film and best supporting actor for Vlad Ivanov.
The movie, about two women procuring an illegal abortion during the Ceausescu era, won the Palme D'Dor earlier this year.
Amy Ryan was awarded best supporting actress for her performances in two films, Gone Baby Gone and Before The Devil Knows You're Dead.
Cate Blanchett, who has already won plaudits for her portrayal of Bob Dylan in I'm Not There, was runner-up in the category.
Michael Moore's documentary Sicko lost the documentary prize to No End In Sight, a film about the Bush administration's handling of the Iraq war by Charles Ferguson.