LOS ANGELES, Feb. 9 (Xinhua) -- Joaquin Phoenix won the Best Actor Award for his performance as a loner clown in psychological thriller film "Joker" at the 92nd Academy Awards ceremony, or the Oscars, held at the Dolby theatre here Sunday night.

This is Phoenix's fourth Oscar nominations but first win, beating out strong rivals including Antonio Banderas ("Pain and Glory"), Leonardo DiCaprio ("Once Upon a Time in Hollywood"), Adam Driver ("Marriage Story") and Jonathan Pryce ("The Two Popes").

Phoenix had already taken home trophies at the Golden Globes, Critics' Choice, Screen Actors Guild, and British Academy Film Awards for his role in the film as Arthur Fleck, a failed stand-up comedian who descended into insanity and nihilism.