(CNN) -- "American Hustle" has stepped up its game.
The comedic film, loosely based on the Abscam scandal of the late '70s, received just two nominations at the 20th Annual Screen Actors Guild Awards Saturday night, but it won the big one: outstanding performance by a cast in a motion picture.
Star Bradley Cooper, practically yelling his approval, paid tribute to director David O. Russell for the film.
"Hustle" and "12 Years a Slave" are among the leading Oscar nominees, and at the SAG Awards the two films faced off for outstanding ensemble -- the SAG Awards' equivalent of Oscar's best picture. Last week, "American Hustle" won the Golden Globe for best comedy or musical film; "12 Years" took home that award for best drama.
"12 Years," about a freeman forced into slavery in 19th-century America, led all SAG Awards nominees with four nominations.
Other winners established themselves as Oscar front-runners as well.
Matthew McConaughey of "Dallas Buyers Club" took home the Screen Actors Guild Award for outstanding performance by a male actor in a leading role Saturday night. He plays an AIDS-afflicted man in the film.
He won the Golden Globe for the same role last week.
Cate Blanchett, who also won a Globe, won the SAG Award for lead female actor.
For Oscar watchers, the awards offer a key indicator of which way the wind is blowing among members of the Motion Picture Academy. The actors' branch is the largest of any of the academy's voting blocs.
The Academy Awards are scheduled for Sunday, March 2.
Winfrey: 'We do movies to move people'
Lupita Nyong'o and Jared Leto led off the awards by winning prizes for supporting female actor and supporting male actor, respectively.
Leto, who stars as a transgender woman in "Dallas Buyers Club," paid tribute to those who have been victims of AIDS, "that terrible disease."
Nyong'o, who plays a slave terrorized by a plantation owner in "12 Years a Slave," won over competition that included Oprah Winfrey ("Lee Daniels' The Butler") and Jennifer Lawrence ("American Hustle").
Winfrey addressed the controversy about not being nominated for an Oscar with CNN's Nischelle Turner on the red carpet.
After praising all the other supporting actress nominees, she pointed out that "The Butler" -- a box-office success -- has had an impact.
"We don't do movies to get awards," she said. "We do movies to move people."
Rita Moreno accepted the Screen Actors Guild's Life Achievement Award on Saturday night.
She and presenter Morgan Freeman fell into their old "Electric Company" roles, pronouncing out "SAG-AFTRA."
Then Moreno got serious.
"It's early in the third act of my life," the 82-year-old Moreno said, and then went into a snippet of "This Is All I Ask": "Let the music play as long as there's a song to sing / And I will stay younger than spring."
'Breaking Bad,' 'Modern Family' win TV honors
Like the Globes, the SAG Awards also nominate television performers.
Nominees for ensemble in a drama were "Boardwalk Empire," "Breaking Bad," "Downton Abbey," "Game of Thrones" and "Homeland."
"Modern Family" won comedy series ensemble. It's the show's fourth straight SAG Award.
"Veep's" Julia Louis-Dreyfus and "Modern Family's" Ty Burrell won SAG Awards for their performances in TV comedies. Michael Douglas ("Behind the Candelabra") and Helen Mirren ("Phil Spector") also took home trophies.
"Breaking Bad" won drama series ensemble and star Bryan Cranston took home the award for male actor in a drama.
Members of the cast of "Downton Abbey" knew what was coming. Before the show, they responded in unison when asked who was going to win.
" 'Breaking Bad,' " they told CNN.
But "Downton's" Maggie Smith did win for female actor in a drama series.
For performers, the Screen Actors Guild Awards represent recognition from their peers. The trophy is even called "the Actor."
But the red carpet gave those performers some challenges.
Sarah Paulson, who was nominated as part of the ensemble with "12 Years a Slave," was dressed in a somewhat flowy white dress. Complimented on the look, she could only laugh.
"(People will say), what's with your weird princess dress?" she said.
And Lawrence had the line of the night for every person who's ever had to get uncomfortable to look good.
Her Dior couture gown, she said, was "squeezing my breasts into my armpits."