"Ocean's Thirteen," released by Time Warner unit Warner Bros. Pictures, is the third film to team Clooney and company with director Steven Soderbergh for a franchise inspired by the 1960 "rat pack" adventure starring Frank Sinatra, Dean Martin and Sammy Davis Jr.
And it is the latest in a flurry of big-studio sequels to arrive in theaters since the unofficial start of the summer movie season last month, following "Spider-Man 3," "Shrek the Third" and this week's No. 2 film, "Pirates of the Caribbean: At World's End."
"For a third installment, and there's been a lot of them this year, that tells you it's still a solid franchise," Paul Dergarabedian, president of box office tracking firm Media By Numbers, said of "Ocean's" performance.
By comparison, "Ocean's Eleven" and "Ocean's Twelve" grossed $38.1 million and $39.2 million during their respective first weekends in December 2001 and 2004, and they went on to amass more than $795 million worldwide together.
The top 12 films at the North American multiplex this weekend collectively grossed $133.6 million, down more than 9% from the same weekend last year when Disney's computer-animated racing film "Cars" opened with $60 million.
But overall domestic box office is up more than 10% year-to-year since May, a sign that the summer sequel formula is working for Hollywood.
Pirate Booty
Disney's third "Pirates" adventure, which had sailed atop the box
office for the past two weekends, sank to No. 2 in its third week with $21.3 million in U.S. and Canadian receipts, according to studio figures compiled by Media by Numbers.
Starring Johnny Depp, Orlando Bloom and Keira Knightley, "At World's End" has grossed a total of $253.6 million in domestic distribution so far.
The bawdy comedy "Knocked Up," from Universal Pictures, slipped a notch to No. 3 but held up relatively well in its second weekend with $20 million in ticket sales, a decline of 35 percent from its opening three-day tally.
Opening behind it at No. 4 was Hollywood's latest computer-animated penguin tale, "Surf's Up," from Sony Pictures Entertainment, grossing $18 million.
The animated storybook satire "Shrek the Third" grossed $15.7 million in its fourth weekend to round out the top five. The DreamWorks Animation SKG film, released through Viacom's Paramount Pictures, has now racked up nearly $282 million in domestic release.
Another of the summer's blockbuster sequels, "Spider-Man 3," fell from fifth place to No. 8 at the domestic box office with $4.4 million in its sixth weekend, bringing its North American tally to $325.7 million.
Its worldwide cumulative gross stands at $865 million, making it Sony's biggest global success.
This weekend's only other wide release, the Lionsgate horror film "Hostel: Part II," opened at No. 6 with $8.8 million in receipts.