Screen Gems is back in good form with thriller The Roommate, which easily beat Universal/Relativity’s 3D Sanctum at the Friday box office in grossing an estimated $6.4 million from 2,534 screens.
Sanctum, executive produced by James Cameron, grossed an estimated $3.6 million from 2,787 runs, including more than 2,000 3D runs. The Australian adventure-thriller also is playing in 178 Imax theaters.

Roommate is looking at a weekend gross of $15 million or more, a strong start for the female-driven pic, which stars Minka Kelly and Leighton Meester. The movie, which cost a modest $16 million to produce, is the first film in weeks to draw a younger crowd. Of the audience, 73% were under the age of 25, helping to explain the film’s strength.

Otherwise, the box office remained sluggish. Bad weather in the South didn’t help, while Chicago is still digging out from the Groundhog blizzard.

Universal and Relativity Media, which partnered in paying $12 million for distribution rights to Sanctum, knew going into the weekend that the film would have a soft debut, despite Cameron’s involvement and higher-priced 3D tickets. Roughly 80% of the audience was over the age of 25.

Sanctum received a C+ CinemaScore; Roommate, a B-.