Michael Moore's Fahrenheit 9/11 followed up its Palme d'Or triumph andcritical adulation with a stunning US box office victory at the weekend as itopened top on an estimated $21.8m.

No documentary has ever opened number one here until now, and thepicture's opening salvo may already have passed the $21.6m final gross ofMoore's previous release and erstwhile documentary record-holder Bowling ForColumbine.

The robust anti-Bush polemicaveraged $25,115 on 868 screens and was distributed through a "coalition of thewilling" comprising Lions Gate, IFC Films and Harvey and Bob Weinstein'sFellowship Adventure Group. Wild Bunch handles international sales.

Fahrenheit 9/11 set all-time opening day records when it opened on Wednesday(23) in New York's Lincoln Plaza and Loews Village 7 and the ensuing nationwide bowrepresents a slap in the face to embattled Disney chief executive officerMichael Eisner.

Eisner told Moore and Disney-owned Miramax Films more than a yearago that he would not allow the picture to be released under the Disneyumbrella, ostensibly for reasons of political balance.

After a potent and carefully planned publicity campaign, theWeinsteins finally bought back the picture from Disney and made alternativedistribution arrangements. The screen-count will expand over the July 4 weekendand again on Jul 9.

"The soul of this movie is that it stands up for our soldiers onthe ground in Iraq by asking the question the majority of Americans wantanswered: why are our soldiers there'" Moore said in a statement.

He continued: "Harvey and Bob are marketing geniuses, but I'veknown that since I first met them 15 years ago. They have been the independentfilm-maker's best friend and, with this film, they have been the best friend ofthe American people.

"Their creative energies, along with our partners at Lions Gateand IFC Films, have ensured that this movie will bring the truth about the lastfour years to a majority of Americans."

"This is a historic achievement from an incredible and courageousfilm-maker. We are proud to be a part of it," the Weinsteins added.

Lions Gate Filmspresident Tom Ortenberg said the result was "a testament to Michael Moore'screative brilliance", while IFC Films chief Jonathan Sehring said the releaseproved that "strong content will win out when challenged by politics."