"Chappie" debuted at No. 1 with an estimated $13.3 million in the U.S. and Canada during a slow box office weekend, while the Vince Vaughn comedy "Unfinished Business" opened at No. 10 with a mere $4.8 million.
Last week's top film, "Focus," fell 46% in ticket sales and finished second with about $10 million. Fox Searchlight's "The Second Best Exotic Marigold Hotel" came in at third with a solid $8.6-million start.
The box office as a whole was down 38.5% compared with the same weekend last year.
"Chappie," from writer-director Neill Blomkamp ("District 9"), follows a robot (Sharlto Copley) with the ability to think and feel for himself. It co-stars Ninja and Yo-Landi Visser (the South African hip-hop duo known as Die Antwoord), Dev Patel, Sigourney Weaver and Hugh Jackman.
"The film definitely played in the realm of our expectations," said Rory Bruer, distribution president of Sony Pictures, which had expected a $14-million opening.
The film cost about $50 million to make. It fared well enough among moviegoers to earn a B-minus grade from audience polling firm CinemaScore. About 60% of the audience was male, and 57% was younger than 30. Critics, however, gave the film a low 30% positive rating on review aggregator Rotten Tomatoes.
"Focus," released by Warner Bros., follows con artist Nicky (Will Smith), who trains and eventually falls for Jess (Margot Robbie). Three years after they break up, the duo reunite in Buenos Aires, where both have come to con the same billionaire. To date, the caper film has made $34.6 million in the U.S. and Canada.
Fox's "Kingsman: The Secret Service" and Paramount Pictures' "The SpongeBob Movie: Sponge Out of Water" held steady in the top five. "Kingsman" came in fourth place with $8.3 million in its fourth weekend of release, and "SpongeBob" finished in fifth with $7 million in its fifth weekend.
Fox Searchlight's "Marigold Hotel" was the highest rated and most praised film of the newcomers: It earned a B-plus rating on CinemaScore and 64% positive rating from Rotten Tomatoes.
The PG film is set just eight months after the first movie concluded. It follows young hotel owner Sonny (Patel) as he hopes to open another hotel while preparing for his marriage. Maggie Smith, Judi Dench and Bill Nighy also reprise their roles.
Its 2012 predecessor, a film about seven British retirees on a trip to India, opened strong and went on to become a breakout hit overseas and in the U.S., grossing nearly $137 million worldwide.
"We're very happy and very encouraged by the opening," Frank Rodriguez, Fox Searchlight's senior vice president of distribution, said of the sequel on Sunday. "It wouldn't even surprise me if today's grosses give us an even higher number. Our matinee numbers will likely be really strong today."
About 65% of the audience for the film was female, and 80% was older than 35.
Rodriguez said the film had strong turnout in "the mature and very metropolitan areas" such as New York and Los Angeles as well as Palm Springs and Florida.
Going into the weekend, Fox had modest expectations for "Unfinished Business." But the film, which cost about $35 million to make, still came in behind the $5-million estimate.
The comedy stars Vince Vaughn, Dave Franco and Tom Wilkinson as three men on a European business trip gone wrong.
The audience skewed male (55%) and older than 25 (54%). The film earned a B-minus grade from CinemaScore, and critics gave the film a 13% positive rating on Rotten Tomatoes.
Vaughn's latest films, "The Internship" and "Delivery Man," also didn't fare well at the box office. "The Internship," released in June 2013, topped out at $44.7 million in the U.S. and Canada. "Delivery Man," released by Disney, grossed $30.7 million.
Though the marketplace is crowded with R-rated films, families will likely return to theaters next weekend for the premiere of Disney's live-action version of "Cinderella."
Despite the weak start to March, robust ticket sales in January and February (including the juggernauts "American Sniper" and "Fifty Shades of Grey") have kept the overall year-to-date box office up about 5% over last year.