Audiences knew what they wanted this weekend: Nicholas Cage and the apocalypse.

Summit Entertainment's supernatural thriller "Knowing," which stars Cage as an astrophysics professor who figures out how to predict monumental catastrophes, debuted as the No. 1 movie at the weekend box office with $24.8 million, according to studio estimates Sunday.

"Knowing" easily foiled "I Love You, Man" and "Duplicity," the other films opening in wide release. "I Love You, Man" was second with $18 million and "Duplicity" was third at $14.4 million.

The victory was another affirmation for Summit Entertainment, the small studio behind the vampire saga "Twilight," which opened last year with more than $69 million and went on sale on DVD Saturday after fans lined up at midnight.

Richie Fay, the studio's president of domestic distribution, said there are several reasons for the studio's successes.

"We've got great creative talent at the studio, veterans on the marketing side and I've got a few years under my belt on the distribution side," said Fay. "It's the right people coming together at the right time. We're lean and mean, but we pack a punch. We can deliver on all levels. With the DVD coming out so well, we're obviously a fully functioning studio."

The "bromantic" comedy "I Love You, Man" attracted equal numbers of men and women, according to the studio. It stars Paul Rudd and Jason Segel

"I think the movie debuted at expectations," said Don Harris, Paramount's vice president of distribution. "We had the advantage of opening at the beginning of college and high school spring break, so the audience for this film is going to continue to be available. We think the movie will have good legs. There are no other comedies coming out for the next couple of weekends, so that bodes well for the film."

The other major debut of the weekend, Universal's romantic comedy "Duplicity," was written and directed by "Michael Clayton" director Tony Gilroy and stars Julia Roberts and Clive Owen as romantically entangled former spies who scheme to steal millions of dollars from their rival pharmaceutical companies.

"I liken 'Duplicity' to cinematic fine dining," said Paul Dergarabedian, president of box office tracker Media By Numbers. "I think 'Knowing' and 'I Love You, Man' were more like fast food. They were fun and easy. 'Duplicity' was just a little bit more of a challenging films for audiences. I think audiences were looking for a different kind of escapism."

Factoring in 2009's higher admission prices, the box office total was down 5 percent compared with last year, the second straight weekend of decline.

Dergarabedian doesn't believe the decline indicates the end of an otherwise stellar year at the box office, however, adding that next weekend's debut of Dreamworks' "Monsters vs. Aliens" should be strong.

"Being only 12 weeks into the year, every weekend makes a huge difference," said Dergarabedian. "We're still doing great this year, but it just shows you that the business is extremely cyclical. I'm not ready to signal any kind of doom and gloom just yet. We have 'Monsters vs. Aliens' opening Friday, and I think that will get us back on track."

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Media By Numbers LLC. Final figures will be released Monday.

1. "Knowing," $24.8 million.

2. "I Love You, Man," $18 million.

3. "Duplicity," $14.4 million.

4. "Race to Witch Mountain," $13 million.

5. "Watchmen," $6.7 million.

6. "The Last House on the Left," $5.9 million.

7. "Taken," $4.1 million.

8. "Slumdog Millionaire," $2.7 million.

9. "Tyler Perry's Madea Goes to Jail," $2.5 million.

10. "Coraline," $2.1 million.