LOS ANGELES (Reuters) - "Saw IV," the latest instalment in the annual horror franchise, sliced and diced its competition at the weekend box office in North America, according to preliminary sales estimates issued on Saturday.

The Halloween staple opened to $14.3 million on Friday, while the new Steve Carell comedy "Dan in Real Life" took the No. 2 spot with $4.1 million, said tracking firm Box Office Mojo (http://www.boxofficemojo.com).

The Friday haul for "Saw IV" was in line with the $14.5 million start for "Saw III" at the same time last year. It went on to make $33.6 million for the weekend, and $80.2 million by the end of its domestic run. The franchise revolves around the antics of a serial killer named Jigsaw (Tobin Bell) with a penchant for killing his victims in gruesome style.

Recent entries in the "torture porn" horror subgenre, such as "Hostel Part II" and "Captivity," have bombed at the box office. But "Saw IV" remains just as potent, a rarity for any film franchise in its fourth iteration. The "Saw" films were released by Lionsgate, a unit of Lions Gate Entertainment Corp.

"Dan in Real Life," from Walt Disney Co., stars Carell as a widowed family-advice columnist who falls in love with his brother's girlfriend, played by Juliette Binoche. Based on its Friday opening, it should earn about $10 million for the weekend, in line with pundits' forecasts.

Last weekend's champ, the Sony Corp. vampire thriller "30 Days of Night," fell to No. 3 with $2.2 million, losing a big chunk of its business to "Saw IV."

Rounding out the top five were two other former chart-toppers, the Disney family comedy "The Game Plan" with $1.8 million, and the Lionsgate romantic comedy-drama "Why Did I Get Married?" with $1.6 million.

Estimates for the weekend will be released on Sunday and final data on Monday.