Fifty Shades Of Grey has romped to the top of the U.S. box office with a stunning $81.7 million (Gbp54.5 million) opening weekend take.

The film adaptation of E.L. James's steamy novel is a huge hit, becoming the highest grossing Valentine's/Presidents Day weekend opener of all time, beating out the 2010 romantic comedy Valentine's Day.

It's also the second-biggest February weekend debut ever, behind Mel Gibson's The Passion of Christ, which opened with $84 million (Gbp56 million) 11 years ago (04).

Fifty Shades has also opened big globally, with an estimated $158 million (Gbp105.3 million) outside America, becoming the biggest R-rated film debut internationally.

Back in the U.S., Colin Firth's new action film Kingsman: The Secret Service also enjoyed success at the cinemas, opening with $35.6 million (Gbp27.3 million).

Last week's number one, The SpongeBob Movie: Sponge Out of Water, falls to three, while American Sniper and Jupiter Ascending round out the new top five.