Los Angeles ? It was another down weekend at the box office, although moviegoers helped Sony Pictures and Dwayne “The Rock” Johnson score with the football flick “Gridiron Gang.”

The drama about a football team at a Los Angeles juvenile detention center took in an estimated $15 million in ticket sales to claim the top spot for the weekend. The debut gave distributor Sony its 10th top opener this year, setting an all-time industry record.

Overall, box office revenues for the top 12 films dipped 12.3 percent from the same weekend last year. That makes for two down weekends in a row, cutting into the single-digit revenue gains the studios has enjoyed so far this year.

Studio revenues are still up 6.2 percent over last year and attendance is also up 3 percent, according to box office tracker Exhibitor Relations Inc.

Despite high expectations from director Brian De Palma and a cast including Josh Hartnett and Scarlett Johansson, the gruesome murder mystery “The Black Dahlia” opened in the second spot with $10.4 million.

The film, from Universal Pictures, fared better than last week’s debut of “Hollywoodland,” which sank from the number two spot to ninth place this week. Both films deal with real-life Los Angeles mysteries.

The animated film “Everyone’s Hero” took in $6.2 million. The 20th Century Fox movie was originally directed by the late Christopher Reeve, and his wife Dana served as producer of the film until her death in March.

The other major film opening was Paramount’s “The Last Kiss,” which took in $4.7 million for fourth place. The movie stars Zach Braff of “Scrubs” and Rachel Bilson of “The O.C.”

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Exhibitor Relations Co. Inc.:

1. “Gridiron Gang,” $15 million.

2. “The Black Dahlia,” $10.4 million.

3. “Everyone’s Hero,” $6.2 million.

4. “The Last Kiss,” $4.7 million.

5. “The Covenant,” $4.7 million.

6. “Invincible,” $3.9 million.

7. “The Illusionist,” $3.8 million.

8. “Little Miss Sunshine,” $3.4 million

9. “Hollywoodland,” $2.7 million.

10. “Crank,” $2.7 million.