Actors Matt Damon, Gwyneth Paltrow and Jennifer Ehle (L-R) pose for photographers on the "Contagion" red carpet at the 68th Venice Film Festival September 3, 2011.[Photo/Agencies]

LOS ANGELES - "Contagion" caught the No. 1 spot at the box office, inhaling $22.4 million in its first weekend.

The Warner Bros. pandemic thriller starring an A-list cast that includes Matt Damon, Kate Winslet, Jude Law and Gwyneth Paltrow topped reigning box office champion "The Help," which earned $8.9 million in its fifth week, bringing the acclaimed Disney drama's domestic haul to $137.3 million.

Despite the infectious success of "Contagion," it was the lowest grossing weekend of the year so far for the film industry, a typical slump for the weekend after Labor Day.

The top 20 movies at U.S. and Canadian theaters Friday through Sunday, followed by distribution studio, gross, number of theater locations, average receipts per location, total gross and number of weeks in release, as compiled Monday by Hollywood.com are:

1. "Contagion," Warner Bros., $22,403,596, 3,222 locations, $6,953 average, $22,403,596, one week.

2. "The Help," Disney, $8,926,142, 2,935 locations, $3,041 average, $137,327,800, five weeks.

3. "Warrior," Lionsgate, $5,242,107, 1,869 locations, $2,805 average, $5,242,107, one week.

4. "The Debt," Focus, $4,772,045, 1,876 locations, $2,544 average, $21,869,001, two weeks.

5. "Colombiana," Sony/Tristar, $3,947,582, 2,354 locations, $1,677 average, $29,726,288, three weeks.

6. "Rise of the Planet of the Apes," Fox, $3,886,285, 2,887 locations, $1,346 average, $167,847,116, six weeks.

7. "Shark Night 3D," Relativity Media, $3,408,413, 2,848 locations, $1,197 average, $14,672,592, two weeks.

8. "Apollo 18," Weinstein Co., $2,851,349, 3,330 locations, $856 average, $14,939,303, two weeks.

9. "Our Idiot Brother," Weinstein Co., $2,650,528, 2,396 locations, $1,106 average, $21,309,547, three weeks.

10. "Spy Kids 4: All the Time in the World," Weinstein Co., $2,501,432, 2,544 locations, $983 average, $34,223,018, four weeks.

11. "Crazy, Stupid, Love.," Warner Bros., $2,261,572, 1,310 locations, $1,726 average, $78,510,633, seven weeks.

12. "Don't be Afraid of the Dark," Film District, $2,166,846, 2,251 locations, $963 average, $21,000,604, three weeks.

13. "Kevin Hart: Laugh at My Pain," Vivendi, $1,908,420, 98 locations, $19,474 average, $1,908,420, one week.

14. "The Smurfs," Sony Animation/Columbia, $1,800,432, 1,977 locations, $911 average, $136,009,277, seven weeks.

15. "Bucky Larson: Born to be a Star," Sony/Columbia, $1,415,023, 1,500 locations, $943 average, $1,415,023, one week.

16. "Harry Potter and the Deathly Hallows: Part II," Warner Bros., $1,001,583, 810 locations, $1,237 average, $377,104,684, nine weeks.

17. "Captain America: the First Avenger," Paramount, $845,653, 804 locations, $1,052 average, $173,459,663, eight weeks.

18. "Cowboys & Aliens," Universal, $827,955, 920 locations, $900 average, $98,041,821, seven weeks.

19. "Seven Days in Utopia," Visio Ent., $649,512, 555 locations, $1,170 average, $2,749,856, two weeks.

20. "Horrible Bosses," Warner Bros., $585,868, 503 locations, $1,165 average, $115,795,823, 10 weeks.