LOS ANGELES (Reuters) - Daniel Day-Lewis was named best actor at the Screen Actors Guild Awards on Sunday and dedicated his trophy to promising Australian actor Heath Ledger, who died at age 28 in New York last week.

Day-Lewis, 50, won for his portrayal of a greedy oil entrepreneur in "There Will Be Blood."

In an emotional acceptance speech, the British actor spoke warmly of Ledger and the roles he had created in films ranging from "Monster's Ball" to "Brokeback Mountain."

Ledger was found dead in his New York apartment on Tuesday. The cause of death is still unclear.

Day-Lewis said that as a reluctant gay cowboy in "Brokeback Mountain," Ledger "was unique. He was perfect."

"I'd like to dedicate this to Heath Ledger," Day-Lewis said to warm applause.

Day-Lewis's win at the SAG awards makes him a favorite for Oscar glory on Feb. 24. His role as a vicious and ambitious oil baron in the early 20th century has been universally praised and has already won him a Golden Globe award.