Will Smith's new sci-fi blockbuster, I Am Legend, has broken all December opening records at the U.s. box office.

The film, in which Smith plays the last man on earth, scored a huge weekend at cinemas and claimed the top spot, with a staggering $72.6 million opening take.

Smith's seventh successive film to debut at number one, I Am Legend beat Lord of The Rings: The Return of The King's 2003 haul to become the best December opener in film history.

Family movie Alvin + The Chipmunks also enjoyed a strong opening weekend, claiming the runner-up spot on the box office chart with an estimated $45 million take.

Last week's charttopper, The Golden Compass, fell to number three with just $9 million.