The Apes still rule.

Universal’s micro-budget chiller “The Purge: Anarchy” brought out the horror-buffs, propelling the sequel to last summer’s break-out hit to a $28.4 million debut from 2,804 locations, but that wasn’t enough to unseat 20th Century Fox’s “Dawn of the Planet of the Apes.” The well-reviewed sequel racked up $36 million in its second week of release, becoming only the second film this summer to hold on to the box office crown for consecutive weekends.

“The Purge:Anarchy” counts as a win for Universal and Blumhouse Productions, the evangelists for lower-cost approach to the horror genre, with the sequel budgeted at a mere $9 million. The film skewed 52% female and was powered by Hispanic audiences, who comprised a leading 36% of ticket-buyers.

“People loved the first one and that’s the main reason people came out to theaters,” said Nikki Rocco, head of domestic distribution at Universal.

Columbia Pictures’ “Sex Tape” went limp this weekend. The Cameron Diaz and Jason Segel cloud-based farce bowed in fourth place to a lackluster $15 million from 3,062 locations, apparently hurt by poor reviews and a glut of R-rated comedies this summer.

“People really like the movie, but I think the title confused some folks and the film is in fact a sweet, funny romantic comedy,” said Rory Bruer, Sony Pictures president of worldwide distribution.

At a cost of $40 million, it will look to foreign markets where Diaz has a strong following to make back its production budget.

Walt Disney’s “Planes: Fire & Rescue” landed with $18 million domestically and $9 million from foreign showings, with the studio hoping that the picture is bolstered by a dearth of family-friendly titles in the coming weeks. An A CinemaScore rating should help with the word-of-mouth, though the picture did debut to less than the $22 million bow of its predecessor, “Planes.”

“From a company perspective, we see it as a good result overall,” said Dave Hollis, Walt Disney Studios’ executive vice president of theatrical distribution. “The value for a property like this is not just measured in box office, it’s seen in video sales and the consumer products space, and this result will only further the great affinity people have for these characters.”

Both “Planes” and “Sex Tape” came in below expectations. The two films had been tracking for a debut north of $20 million, but may have been weighed down by a downturn in domestic ticket sales.

“We may have been the victim of a bit of a momentum issue overall,” said Hollis.

“Transformers: Age of Extinction” continued to truck along, pulling in another $10 million and pushing its domestic total to $227 million.

In limited release news, IFC’s “Boyhood” continued to benefit from a rapturous critical reception. Richard Linklater’s look at one boy’s development into manhood expanded from five theaters to 34 screens, earning $1.2 million. It expands to the top 25 major markets next weekend.

Michel Gondry’s latest head trip of a movie, “Mood Indigo” debuted to $25,000 in two theaters, while Fox Searchlight’s “I Origins” racked up $28,700 from four theaters.

Zach Braff’s Kickstarter-funded “Wish I Was Here” opened to $495,000 in 68 theaters. Focus Features will expand the film to 600 theaters to see if it can build it into another “Garden State.”

Overall, the box office was down 24% from the same weekend a year ago, when “The Conjuring” debuted to $41.8 million, dragging 2014’s ticket sales off by 6.1% from the previous year. Next week brings the release of two action films, “Hercules” and “Lucy,” and the chance to recapture some of the box office momentum that has been lost in recent weeks.