The Batman Begins sequel The Dark Knight has set another record at the box office by becoming the first film to pass the $300 million in just 10 days. The film became the first movie to hit the $200 million mark in five days after breaking all opening-weekend box office records last week . Thanks to a staggering $75.6 million second weekend take, the Batman film has racked up over $314 million since its release in America 10 days ago. It took previous record holder Pirates Of The Caribbean: Dead Man's Chest 16 days to pass the $300 million mark in 2006. Meanwhile, Will Ferrell's new comedy Step Brothers opened big in second place with a $30 million opening weekend take and Abba movie musical Mamma Mia! slipped to third with $17.9 million. The new X-Files film, The X Files: I Want To Believe, was a disappointment in its first weekend on release - it took in just $10.2 million.