'Riddick' opens at No. 1 at U.S. box office 8 (UPI) -- "Riddick," the new sci-fi movie starring Vin Diesel, was No. 1 in its first week in release with $18.7 million, U.S. box-office estimates indicate. "Lee Daniels' The Butler," which had been No. 1 for three weeks, slipped to No. 2 with an estimated $8.9 million and a four-week total of $91.9 million, Box Office Mojo reported. "Instructions Not Included" was third with $8.1 million, followed by "We're the Millers" with $7.9 million and "Planes" with $4.3 million. "One Direction: This is Us" ($4.1 million), "Elysium" ($3.1 million), "Blue Jasmine" ($2.7 million) "Percy Jackson: Sea of Monsters" ($2.5 million) and "The World's End" ($2.3 million) completed the Top 10.