‘Monsters vs. Aliens’ is #1 at the box office!

DreamWorks Animation’s action comedy “Monsters vs. Aliens,” which features creatures from 1950s flicks in a showdown with invading extraterrestrials, launched itself into the No. 1 spot with a $58.2 million debut, according to studio estimates Sunday.

It was the biggest debut so far in 2009, topping the $55.2 million first weekend of “Watchmen” in early March.

Opening in second place was Lionsgate’s ghost story “The Haunting in Connecticut” with $23 million in ticket sales.

The previous weekend’s top movie, Summit Entertainment’s apocalyptic thriller “Knowing,” slipped to third with $14.7 million, raising its 10-day total to $46.2 million.

The big opening for “Monsters vs. Aliens” boosted Hollywood revenues after a couple of down weekends.

“Monsters vs. Aliens” was the latest success story for digital 3-D projection. While the 2,080 3-D screens accounted for just 28 percent of the roughly 7,300 on which the movie played, they made up 56 percent of its total box-office haul, said Anne Globe, head of marketing for DreamWorks Animation.

Tickets for 3-D movies typically cost a few dollars more than the 2-D version.

1. “Monsters vs. Aliens,” $58.2 million.

2. “The Haunting in Connecticut,” $23 million.

3. “Knowing,” $14.7 million.

4. “I Love You, Man,” $12.6 million.

5. “Duplicity,” $7.6 million.

6. “Race to Witch Mountain,” $5.6 million.

7. “12 Rounds,” $5.3 million.

8. “Watchmen,” $2.755 million.

9. “Taken,” $2.75 million.

10. “The Last House on the Left,” $2.6 million.