LOS ANGELES - Movie-goers went hunting for their inner caveman on the weekend, spending $35.7 million to give the prehistoric adventure "10,000 B.C.'' top spot at the box office, according to studio estimates Sunday.

The Warner Bros. visual effects spectacle, which follows a band of people struggling to survive amid woolly mammoths, sabre-toothed tigers and human marauders, also took in $25.3 million in 20 overseas markets where it began rolling out Wednesday.

Opening in second place was the Martin Lawrence comedy "College Road Trip,'' which pulled in $14 million on the weekend at theatres in the United States and Canada.

The Disney offering stars Lawrence as an overprotective dad who tags along with his daughter (Raven-Symone) on her girls-only trek to choose a college.

Both movies put in decent numbers despite bad reviews.

"10,000 B.C.'' came in well behind the openings of past blockbusters from director Roland Emmerich.

His previous hits have included "Independence Day'' and "Godzilla,'' with his best debut coming four years ago with "The Day After Tomorrow,''  which hauled in $68.7 million in its opening weekend.

"Those movies opened up in the summer; we're very strong for this time of year,'' said Dan Fellman, head of distribution for Warner.

Fellman said Emmerich's films tend to do better internationally, including "The Day After Tomorrow,'' which topped out at $186.7 million domestically and did nearly twice that business overseas.

"10,000 B.C.'' opened at No. 1 in 19 of its 20 foreign markets, among them Spain, Mexico, Germany and Australia, said Veronica Kwan-Rubinek, head of international distribution for Warner.

Overall, business was off compared with the same time frame a year ago, an almost inevitable decline given that the blockbuster "300'' opened with $71 million over that weekend in 2007.

The top-12 movies took in $91.8 million, down 34 per cent from the same weekend last year.

It was the fourth consecutive weekend that revenues fell, cutting into a surge in movie-going earlier this year. Attendance is up just 0.5 per cent so far in 2008 compared with a year ago, according to box-office tracker Media By Numbers.

"The advantage we've been enjoying over the last couple of months has really taken a punch in the gut,'' said Paul Dergarabedian, president of Media By Numbers.

The previous weekend's top flick, New Line Cinema's basketball comedy "Semi-Pro'' starring Will Ferrell, tumbled to fourth place with $5.8 million. That brought its 10-day total to just $24.7 million, a poor showing for a Ferrell comedy.

Debuting at No. 5 was Lionsgate's heist thriller "The Bank Job,'' which opened with $5.7 million. Jason Statham stars as a former crook drawn back to a life of crime when he's lured into robbing a Lloyd's of London bank vault.

In narrower release, Focus Features' 1930s comedy "Miss Pettigrew Lives for a Day,'' opened with $2.5 million in 535 theatres for an average of $4,750 a cinema, compared with $10,478 in 3,410 theatres for "10,000 B.C.'' and $5,174 in 2,706 locations for "College Road Trip.''

"Miss Pettigrew'' stars Frances McDormand as a destitute British governess who bluffs her way into a gig as social secretary to a flighty American actress (Amy Adams).

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theatres, according to Media By Numbers LLC. Final figures will be released Monday.

1. "10,000 B.C.,'' $35.7 million.

2. "College Road Trip,'' $14 million.

3. "Vantage Point,'' $7.5 million.

4. "Semi-Pro,'' $5.8 million.

5. "The Bank Job,'' $5.7 million.

6. "The Spiderwick Chronicles,'' $4.8 million.

7. "The Other Boleyn Girl,'' $4 million.

8. "Jumper,'' $3.8 million.

9. "Step Up 2 the Streets,'' $3 million.

10. "Fool's Gold,'' $2.8 million.