Borat, a mockumentary featuring a spoof Kazakh reporter, has topped the North American box office chart on its weekend debut.

The film, starring British comedian Sacha Baron Cohen as Borat, generated an impressive $26.4m between Friday and Sunday.

Borat, which debuted in just 837 cinemas, had been expected to open in fifth place with takings of just $12m.

Santa Clause 3: The Escape Clause entered the US film chart in second place with a disappointing weekend take of $20m, according to figures from tracker Exhibitor Relations.

The second installment of the Santa Clause franchise opened with $29m in 2002.

Animated comedy Flushed Away, featuring the voices of Hugh Jackman and Kate Winslet, debuted at number three, taking $19.1m.

Last weekend's top movie, gory horror Saw III, slipped to fourth spot with ticket sales of $15.5m.

Martin Scorcese's gangster drama The Departed finished in fifth place with an estimated $8m.

Director Christopher Nolan's magical thriller The Prestige, starring Christian Bale and Scarlett Johansson, ranked sixth with earnings of $7.8m.

Clint Eastwood's World War II drama Flags of Our Fathers dropped three places to seventh with $4.5m.

Comedy Man of the Year, starring Robin Williams, came eighth, with Open Season ninth and The Queen tenth.

Takings for the top 12 movies in the US box office were down 5 per cent from the same weekend last year.

This weekend sees the release of Babel, a thriller starring Brad Pitt, and Iraq in Fragments, a documentary about modern day Iraq.