Journalism drama Spotlight won the SAG film ensemble cast award in a night that was dominated by diverse winners.
Spotlight, the story of the Boston Globe's investigation into pedophile priests, won the cast award over Beasts of No Nation, The Big Short, Straight Outta Compton and Trumbo. Demi Moore presented the trophy at the conclusion of ceremonies at the Shrine Auditorium.
Solidifying his frontrunner status, Leonardo DiCaprio won the SAG Award for best actor for The Revenant for his role as a fur trapper bent on revenge. He thanked the actors who came before him, adding, "We stand on the shoulders of giants."
SAG voters have backed the last 11 winners of the best actor Oscar, including Eddie Redmayne last year for The Theory of Everything.
Brie Larson won the best actress for her role as a tormented mother in Room caring for a small boy, played by Jacob Tremblay. She said the part taught her about loving a child.
"When you share your vulnerabilities, it's a way of connecting with the world," she added.
In a rebuke to the all-white Oscar nominations in the acting categories, Idris Elba won the supporting actor SAG Award for Beasts of No Nation, along with a second award for his role in Luther in the TV movie/miniseries category.
"Welcome to diverse TV," he said in his acceptance speech.
The awards were based on voting by the 116,741 dues-current SAG-AFTRA members. Balloting was open during the #OscarsSoWhite backlash and closed Friday.
Diversity continued to rule with Netflix's multi-racial Orange is the New Black taking two awards and transgender-themed titles Transparent and The Danish Girl winning trophies. Viola Davis won the female drama series award for How to Get Away with Murder for the second year in a row.
The win for Spotlight gives the Open Road release significant momentum as the awards season heads into its final weeks. The Big Short won the Producers Guild of America's Darryl F. Zanuck Award for top movie a week ago.
The winner of the SAG ensemble trophy has matched the Oscar best picture winner just ten times in 20 years. Birdman won the SAG and best picture awards last year while American Hustle won the SAG cast award and was shut out at the Oscars two years ago. Argo won both awards three years ago.
Actors are by far the largest branch of the Academy of Motion Picture Arts and Sciences with nearly 20% of the 6,856 members.
Elba said of Beasts of No Nation in his acceptance speech, "We made a film about real people and real lives. Thank you for giving this film some love."
Elba did not receive an Oscar nomination for the Beasts role -- one of the most widely cited reasons why there was a strong negative reaction to the 20 acting Oscar nominations going only to white actors on Jan. 14.
Elba, who portrayed a commandant in a brutal African conflict, won over Christian Bale for The Big Short, Mark Rylance for Bridge of Spies, Michael Shannon for 99 Homes and Jacob Tremblay for Room.
On receiving the second award as an obsessive -- and self-destructive -- detective chief inspector for BBC America's Luther, Elba said, "Two awards -- I don't know what to say" after thanking the producing team behind the crime drama.
Alicia Vikander won the SAG Award for her supporting actress role in The Danish Girl. In what's regarded as one of the closest categories, Vikander topped Rooney Mara for Carol, Rachel McAdams for Spotlight, Helen Mirren for Trumbo and Kate Winslet for Steve Jobs.
The SAG Awards has been a strong indicator of the individual Oscar acting categories. The four awards have matched in the past three years but that won't be case in the supporting category this year with Elba's win of a SAG Award.
Orange is the New Black dominated the comedy series trophies at the SAG Awards, winning the ensemble cast and the female actor award for Uzo Aduba.
Netflix's wins for Orange is the New Black and Aduba mark the second year in a row that the show has taken those categories. The streaming service also boasted winner Kevin Spacey, who won best actor in a drama series for House of Cards for the second year in a row.
Downtown Abbey won the drama series cast award for the second year in a row.