Liongate’s action thriller “Bangkok Dangerous” managed to knock off Ben Stiller’s comedy “Tropic Thunder,” which had held the No.1 spot at the box office the past three weekends, and hit the top of the North American box office in its opening weekend.

However, the new version of the Pang brothers' original Thai film finished first with the lowest gross for a No. 1 movie in five years ($7.8 million). It hardly surpassed its rival for the first place, which grossed $7.5 million.

According to box-office tracker Media by Numbers, this weekend's top 12 films made an estimated $51.6 million, which were the lowest takings in seven years, even for the usually slow weekend after Labor Day.

The last weekend with such poor gains was the weekend after Labor Day in 2003, when the highest-grossing film was the David Spade flick “Dickie Roberts: Former Child Star.”

"It's like clockwork. We always see a pretty heavy slowdown," said Paul Dergarabedian, president of Media by Numbers, according to the Los Angeles Times. "But this year was really significantly slow -- people were distracted by [political] conventions, the weather and the fall television season."

Liongate, the company that owned the distribution rights for the box office winner, said it was not disappointed with the figures that “Bangkok Dangerous” earned.

“It performed within our range of expectations,” said Steve Rothenberg, the studio's president of domestic distribution. “We'll make a nice profit with the movie.”

Analyzers of the movie industry had predicted the film would earn more than $10 million.

The film was not screened in advance for critics, which is almost always a sign that the film does not have much to offer.

Based on the Pang brothers’ 1999 film, “Bangkok” features Nicolas Cage as a cold-blooded assassin who decides to quit his dangerous job, but not before accepting a last mission. He must travel to Thailand to kill six targets. But, after meeting a cute, deaf pharmacist, Fon, he becomes more sensitive and starts wondering whether his way of life is the right one.

Controversial comedy “Tropic Thunder,” which lost its top position and came in second at the box office, earned $7.5 million in its fourth week in theaters and a total of $96.8 million.

The third spot was occupied by Anna Faris’ “The House Bunny,” with $5.9 million. The film raised its total at $37 million after three weeks.

Closing the top five were “The Dark Knight,” on the fourth spot with $5.7 million and the espionage drama “Traitor,” with $4.7 million.

“The Dark Knight” managed to raise its cumulative total to $512 million, which makes it the second best-grossing film after “Titanic.”