The ComingSoon.net Box Office Report has been updated with studio estimates for the weekend. Click here for the full box office estimates of the top 12 films and then check back on Monday for the final figures based on actual box office.

It can be difficult for any movie to do big business once August hits, let alone grossing over $35 million in a single weekend. It's even harder when a movie isn't a franchise sequel, has no bankable stars and is helmed by an unknown director. And yet, that's exactly what happened this weekend as Neill Blomkamp's sci-fi epic District 9 (Sony), starring Sharlto Copley, made with a production budget of just $30 million, dominated the box office with an opening weekend of roughly $37 million in 3,049 theaters, averaging an impressive $12 thousand per site. The combination of buzz from the movie's unique viral marketing department, solid reviews and the direct involvement of master filmmaker Peter Jackson certainly helped convinced people to go out to the theaters to see it.

Dropping 59% to second place in its second weekend, Stephen Sommers' action movie G.I. Joe: The Rise of Cobra (Paramount) added another $22.5 million to bring its total to $98.8 million after ten days. Overseas, "G.I. Joe" topped the box office with an additional $26.2 million for a total of $91.5 million. The film has earned $190.5 million worldwide in 10 days.

Also opening this weekend, Eric Bana and Rachel McAdams starred in Robert (Flightplan) Schwenke's adaptation of the Book Club favorite The Time Traveler's Wife (New Line/WB). It took third place with $19.2 million in just under 3,000 theaters.

The Meryl Streep-Amy Adams cookbook biopic Julie & Julia (Sony) grossed roughly $12.4 million in its second weekend, off 38% from last weekend as it dropped to fourth place.

Taking fifth place, Jerry Bruckheimer's 3D animated animal action adventure G-Force (Disney) edged closer to $100 million with another $6.9 million over the weekend.

Jeremy Piven starred in the long-delayed Gary Sanchez Productions comedy The Goods: Live Hard * Sell Hard (Paramount Vantage), which brought in a disappointing $5.3 million as it debuted in 1,838 theaters.

The sixth installment of Warner Bros.' hit franchise Harry Potter and the Half-Blood Prince dropped to seventh place with $5.2 million for a five-week gross of $284 million.

In eighth place, the Sony comedy The Ugly Truth, pitting Katherine Heigl against Gerard Butler, took in $4.5 million to bring its total to $77.5 million.

Hayao Miyazaki's latest animated fantasy Ponyo (Disney) was released into 927 theaters on Friday, the widest release for a Miyazaki film in the United States, helping it take ninth place with $3.5 million.

Marc Webb's (500) Days of Summer (Fox Searchlight) rounded out the Top 10 with $3 million, having grossed just under $18 million to date.

Opening outside the top 10, Summit's musical Bandslam (Summit), starring Vanessa Hudgens, bombed with just $2.3 million in 2,121 theaters, a pitiful average of roughly a thousand per site.

The Top 10 grossed roughly $119 million, up 12% from the same weekend last year when Ben Stiller's war comedy Tropic Thunder topped the box office with $25.8 million.

In limited release, the Ashton Kutcher indie Spread (Anchor Bay) opened in 91 theaters, grossing just $117 thousand, while Davis Guggenheim's rock doc It Might Get Loud grossed an estimated $101 thousand opening in just 7 theaters.

Click here for the full box office results of the top 12 films.