Clooney, 44, won the best supporting actor award. He also is nominated this year in the director and original screenplay categories for "Good Night, and Good Luck." 　　

Heading into the ceremony, Clooney was widely expected by Oscar watchers to be shut out of those two categories against favorites for movies such as "Brokeback Mountain." 　　　　

"Wow. So I'm not winning director," Clooney quipped in his acceptance speech before paying tribute to his four fellow nominees in the best supporting actor category, saying they had all given "stellar performances." 　　

Clooney's Oscar win cemented his journey from the man once dubbed the "sexiest man alive" by People magazine to a leading Hollywood heavyweight with a passion for making films on risky subjects. 　　

He is also one of Hollywood's best known liberals and an actor who has no qualms about wearing his political heart on his sleeve. 　　

OUT OF TOUCH 　　

"We are a little bit out of touch in Hollywood every once in a while," Clooney acknowledged referring to an earlier joke by Oscar host Jon Stewart. 　　

"We were the ones who talked about AIDS when it was being whispered. We talked about civil rights when it wasn't really popular," he said. 　　

"I'm proud to be part of this Academy. I'm proud to be part of this community. I'm proud to be out of touch," Clooney added.

For his role as U.S. spy Bob Barnes, the handsome leading man gained more than 30 pounds (13.6 kg) to look the part of a haggard man. While filming a scene in which his character is tortured, Clooney was injured and needed several surgeries after rupturing his spinal fluid sack. 　　

Clooney first won fame in the television hospital drama "ER." Since leaving the show, he has appeared in high-profile movies such as 2000's "The Perfect Storm" and subsequently in "Ocean's Eleven" and "Ocean's Twelve." 　　　

He has suffered a few flops, too, such as science-fiction drama "Solaris" and his turn as superhero Batman in 1997's "Batman & Robin" was panned by movie reviewers. 　　

He proved a critics' darling in the Coen brothers' low-budget comedy "O Brother, Where Art Thou?" and for the first time Clooney directed and starred in a film in 2002, "Confessions of a Dangerous Mind." 　　

Clooney is the nephew of the late singer Rosemary Clooney and the son of a TV newscaster, Nick Clooney, who worked in Cincinnati, Ohio.