AceShowbiz -

"Unknown" has apparently been the most recognized movie in theaters this weekend leading to President's Day. The thriller leads North American Box Office with $21.8 million with 89|percent| of the audience over the age of 25 and 54|percent| over 50.

"I'm happy for Joel [Silver-producer] to have a breakout film. Dark Castle has struggled at the box office the past couple of years, and this helps turns things around," Dan Fellman, president of domestic distribution for Warner Bros. which distributes the film, says. "We were up 32|percent| on Saturday, which is a big jump for an adult movie. People really liked it."

"Unknown" 's win comes as a surprise since DreamWorks and Touchstone's "I Am Number Four" was expected to top the chart. The teen sci-fi film opens with $19.4 million, which falls short from analysts' expectations of $23 million, despite an advertising blitz designed to make it a "Twilight" for boys.

Still, Disney worldwide president of distribution, Chuck Viane, could see it positively. "It was an extremely competitive weekend, and we still have two days [Sunday and Monday] to see how all the films play out," he says of the movie which lures younger moviegoers with 68|percent| of the audience between the ages of 12 and 34.

"Gnomeo and Juliet" stays on number three with $19.2 million or dropping just 24.2|percent| from last weekend's haul. "Just Go with It" which topped the chart last week is now on the fourth with $18.5 million. Rounding up the top five is another newcomer "Big Mommas: Like Father, Like Son" with $16.2 million gross.

Top Ten Movies at Box Office for February 18-20:

1. "Unknown" - $21.8 million
2. "I Am Number Four" - $19.4 million
3. "Gnomeo and Juliet" - $19.2 million
4. "Just Go with It" - $18.5 million
5. "Big Mommas: Like Father, Like Son" - $16.2 million
6. "Justin Bieber: Never Say Never" - $13.3 million
7. "The King's Speech" - $6.5 million
8. "The Roommate" - $3.9 million
9. "The Eagle" - $3.6 million
10. "No Strings Attached" - $3.1 million