Will Smiths 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 (GBP36.3 million) opening take. Smiths seventh successive film to debut at number one, I Am Legend beat Lord of The Rings: The Return of The Kings 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 (GBP22.5 million) take. Last weeks (09Dec07) charttopper, The Golden Compass, fell to number three with just $9 million (GBP4.5 million).