LOS ANGELES: Critics loved it and so did America. X-Men: First Class was tops at the North American box office in its opening weekend, bring in some $56 million. The fifth X-Men movie was a winner all around for fans and critics, who have compared it to The Dark Knight as a top level superhero film for the genre. The prequel stars James McAvoy and Michael Fassbender as Professor X and Magneto in roles previously played by Patrick Stewart and Ian McKellen. Debuts for the last three films ranged from $85.1m-$102.8m, but those were released over holidays, so this opening weekend, squeezed between Thor and the upcoming Green Lantern, have shown the movie to be a large success. Distributor News Corp said a “new chapter” of the franchise had been “successfully launched.” The film also stars Jennifer Lawrence, Kevin Bacon and Mad Men actress January Jones, deals with the formative years of its main characters. The release of the X-Men film pushed each of last week's top five movies down a place. The Hangover: Part II – at number two – took $32.4 million in its second weekend. King Fu Panda 2, in third, took $24.3 million and, at number four, Pirates of the Caribbean: On Stranger Tides, took $18 million. The only non-sequel in the top five, Bridesmaids, took $12.1 million. BM