Matthew McConaughey's "Sahara" (search) heated up the weekend box office, with the action flick set in the African desert debuting at the top with $18.5 million. Audiences gave a cooler reception to "Fever Pitch," the weekend's other new wide release.

The Drew Barrymore and Jimmy Fallon (search) baseball romance opened in third place with a so-so $13 million, according to studio estimates Sunday.

The previous weekend's No. 1 movie, "Sin City," (search) slipped to second place with $14.1 million, lifting its 10-day total to $50.7 million.

In limited release, Stephen Chow's raucous action comedy "Kung Fu Hustle" had a big opening with $293,025 in seven theaters, averaging a whopping $41,861 per cinema. "Sahara" averaged $5,866 in 3,154 theaters, and "Fever Pitch" reaped $3,979 in 3,267 locations.

Already a hit in Asia, "Kung Fu Hustle" features writer-director Chow as a two-bit crook in pre-revolution China whose antics land him in the middle of a showdown between mobsters and martial-arts heroes. "Kung Fu Hustle" expands to nationwide release April 22.

Hollywood's box-office slump continued as overall revenues remained down for the seventh-straight weekend. The top 12 movies took in $80.3 million, off 18 percent from the same weekend last year.

Revenues for the year have fallen slightly behind those of 2004, when Hollywood rang up record domestic grosses of $9.4 billion.

"Sahara," adapted from Clive Cussler's adventure novel, stars McConaughey, Penelope Cruz and Steve Zahn as adventurers who turn up a long-lost Civil War vessel in the desert and try to stop a plague spreading through Africa.

Distributor Paramount had expected the movie to debut in the $15 million range, said Wayne Lewellen, head of distribution.

"This is a good, solid opening I think for this film," Lewellen said. "It played well particularly in the middle of the country, which always bodes well for it holding up."

"Fever Pitch," directed by the Farrelly brothers from Nick Hornby's memoir about his sports obsession, stars Barrymore as a career woman who stumbles into a relationship with a man whose world revolves around the Boston Red Sox.

"It may have alienated guys with too much romance, and it may have alienated women with too much baseball," said Paul Dergarabedian, president of box-office tracker Exhibitor Relations.

But women made up 58 percent of the audience for "Fever Pitch." That may bode well for the movie's long-term prospects, since films appealing to women often have a longer shelf life than movies aimed at men.

"These romantic comedies tend to leg out. They play on and on," said Bruce Snyder, head of distribution for 20th Century Fox, which released "Fever Pitch." Barrymore's "Never Been Kissed" had an $11.4 million opening weekend and held on to do a solid $52.4 million when its domestic run ended, he said.

Estimated ticket sales for Friday through Sunday at North American theaters, according to Exhibitor Relations Co. Inc. Final figures will be released Monday.

1. "Sahara," $18.5 million.

2. "Sin City," $14.1 million.

3. "Fever Pitch," $13 million.

4 (tie). "Beauty Shop," $7.1 million.

4 (tie). "Guess Who," $7.1 million.

6. "Robots," $4.65 million.

7. "Miss Congeniality 2: Armed and Fabulous," $4.1 million.

8. "The Pacifier," $3 million.

9. "The Ring 2," $2.9 million.

10. "The Upside of Anger," $2.6 million.