Adult moviegoers fueled the box office this holiday weekend as the Liam Neeson thriller "Unknown" easily topped fellow newcomer "I Am Number Four" for no. 1.

"Unknown" grossed an estimated $21.8 million for the three-day frame and should end up with around $26 million by President's Day.  With a reported 89% of the audience over 25 and a whopping 54% over 50, the thriller recruited a demo that rarely comes out on a film's opening weekend this strongly. 

Pre-release polling indicated that "I Am Number Four" would be the champ, but that wasn't the case as the DreamWorks came in with a less than expected $19.5 million.  The Sci-Fi thriller barely beat fellow Disney stablemate "Gnomeo and Juliet" which found $19.4 million in its second weekend.  The Elton John produced family flick continues to be fueled by strong word of mouth and should surpass "Number Four" for the second slot by the end of the four-day holiday.  Down just 23% from its debut, "Gnomeo" has made a very satisfying $50.4 million in just 10 days.

Another film that could surpass "I Am Number Four" by Monday is the Adam Sandler and Jennifer Aniston comedy "Just Go With It."  The critically lambsted picture found another $18.2 million for a new gross of $60.7 million.

The fifth slot belonged to "Big Mommas: Like Father, Like Son" with $17 million.  With a budget of just $32 million, this New Regency/20th Century Fox release should actually break even when all is said and done.

Last week's no. 2 film, "Justin Bieber Never Say Never," dropped 53% from its opening to find another $13.6 million for a new cume of $48.4 million.  The 3D concert film should easily surprass the $60 million mark in the next few weeks and be a nice profit center for Paramount Pictures which spent just $13 million to produce the pseudo doc.

Also worth noting, "The King's Speech" has now grossed $103.2 million and "Black Swan" reached $101 million, each easily surpassing best picture competitor "The Social Network's" $96.6 million total.  "No Strings Attached" has hit $66 million, "True Grit" has made $164 million, "The Fighter" is at $87 million, "The Green Hornet" has beat up $95 million (Sony appears to be keeping it in theaters as long as possible to hit $100 million), "Blue Valentine" has found a very good $8.8 million in no more than 450 theaters and "Tron Legacy" has quietly reached $170 million.

Actual box office results will be available on Tuesday after the President's day holiday.