The 20th Century Fox movie, which lampooned last year's epic blockbuster "300," took in an estimated $18.7 million in its weekend debut. It edged out "Rambo," a Lionsgate release starring and directed by Sylvester Stallone, which took in $18.2 million.

"This was a very tight race for the No. 1 spot," said Paul Dergarabedian, president of box office tracker Media By Numbers. "I think we tend to underestimate films like 'Meet the Spartans.' Fox has really locked onto something that's extremely popular."

"Spartans" tells the tale of hero Leonidas who leads a group of 13 Spartans to defend against the invading Persians - including Rocky Balboa, Paris Hilton and other pop culture icons. It was directed by Jason Friedberg and Aaron Seltzer, who produced the parodies "Epic Movie" and "Date Movie."

"Spartans" was popular among teenagers and young adults, who made up about 75 percent of the audience. The film was rated PG-13, while R-rated "Rambo" was popular with older men.

"We are thrilled with the numbers," said Bert Livingston, senior vice president of distribution at Fox. "We made it for young people and they came."

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

1. "Meet the Spartans," $18.7 million

2. "Rambo," $18.2 million

3. "27 Dresses," $13.6 million

4. "Cloverfield," $12.7 million

5. "Untraceable," $11.2 million

6. "Juno," $10.3 million

7. "The Bucket List," $10.2 million

8. "There Will be Blood," $4.9 million

9. "National Treasure: Book of Secrets," $4.7 million

10. "Mad Money," $4.6 million

by The Associated Press