The dwarfs and elves of The Hobbit overpowered Tom Cruise to take the box office title for a second time, grabbing US$37.6 million in US and Canadian ticket sales as a crowd of new films fought for pre-holiday audiences.
Cruise's crime drama Jack Reacher, a film about a fatal sniper attack, landed in second place with US$15.6 million.
In third place, adult comedy This is 40 pulled in US$12 million, according to studio estimates compiled by Reuters.
North Americam ticket sales for The Hobbit: An Unexpected Journey fell by about 57 percent during the film's second weekend.
Movie receipts typically drop 40 percent to 60 percent each week.
In international markets, Hobbit sales reached US$284 million and brought the movie's global take to US$434 million, distributor Warner Bros. said.
The Hobbit is the first of three movies based on the classic J.R.R. Tolkien novel set in the fantasy world of Middle Earth.
The films, produced by MGM and Warner Bros.' New Line Cinema, are prequels to the blockbuster Lord of the Rings franchise that brought in box office gold a decade ago.
Producers of The Hobbit and other films hope to enjoy a big boost this week around the Christmas and New Year's holidays.
Sales over the coming days are expected to push 2012 to a domestic box office record. The year is on track to finish with US$10.8 billion worth of ticket sales in the North American market, according to a projection from box office tracker Hollywood.com.
The current record is US$10.6 billion, set in 2009.
Over the weekend, Jack Reacher debuted just days after the Newtown, Connecticut, school shooting sparked new debate about the impact of movie violence.
Reacher begins with a sniper killing a handful of seemingly random victims. A red-carpet premiere and a screening to promote the US$60-million production were postponed after the Newtown tragedy.
''We opened pre-Christmas with our eyes wide open,'' said Don Harris, Paramount's president of domestic distribution, adding that he expected the film's box office take to grow over the coming weeks.
He said the Newtown shooting had ''no effect'' on the movie's opening.
Before the weekend, the studio had predicted sales of US$12 million to US$15 million.
Adult comedy This is 40 stars Paul Rudd and Leslie Mann as a middle-aged couple. The studio billed the US$35 million production from Bridesmaids producer Judd Apatow as a ''sort-of sequel'' to 2007 comedy Knocked Up.
The president of domestic distribution for Universal, Nikki Rocco, said the film exceeded the studio's estimates for opening prior to a mid-week Christmas, and dismissed talk of a Judd Apatow slump since his comedy Bridesmaids, which opened to US$26.3 million in May 2011.