In a major upset, the new kiddie superhero action comedy "Kick-Ass" failed to take the top spot at the North American box office, narrowly losing the race to "How to Train Your Dragon," according to studio estimates issued on Sunday. "Dragon," a cartoon that also opened disappointingly four weekends ago but has held on strongly, earned $20 million for the three days beginning Friday. "Kick-Ass" followed with $19.8 million. Another new release, the Chris Rock comedy "Death at a Funeral," came in at No. 4 with a solid $17 million, just behind "Date Night" with $17.3 million. Rankings could change when final data are released on Monday; that was the case last weekend when "Date Night" claimed the No. 1 spot on Sunday, but was usurped by reigning champion "Clash of the Titans" the next day. Industry forecasters had expected "Kick-Ass" to open in the $25 million-$30 million range. Aaron Johnson stars as a high-school student who transforms himself into a hapless, homemade superhero. Chloe Moretz co-stars as a combat-trained preteen girl, and Nicolas Cage as her father. Reviews were strong, but the "R" rating in the United States, blocking admission to unaccompanied children under 17, likely hit sales, said David Spitz, executive vice president for distribution at distributor Lionsgate. Spitz, emboldened by the holding power of "Dragon," predicted "Kick-Ass" would "play and play and play" in coming weeks. "The 'definite recommends' (from exit polling) are through the roof compared to the norms," Spitz said. The film previously opened below forecasts in Britain, Australia and New Zealand, but has also held up, he added. Lionsgate, a unit of Lions Gate Entertainment Corp., paid $25 million for the rights. Spitz said the film would be profitable for the company, which is evaluating a hostile $7 per share takeover bid by Carl Icahn. The billionaire investor has criticized the company's spending. Lions Gate stock rose 50 cents to $6.87 on Friday. "How to Train Your Dragon" has now earned $158.6 million after four weekends. Sales dropped just 20 percent from last weekend, when it ranked at No. 3. Among other recent big films, "Alice in Wonderland" was off 48 percent in its fourth weekend, and "Avatar" 27 percent. The stock of the film's producer, DreamWorks Animation SKG Inc, has recovered a little after tumbling eight percent to $39.34 the day after the film opened at No. 1 with a modest $44 million. It traded at $40.79 on the Nasdaq on Friday. DreamWorks Animation releases are distributed by Paramount Pictures, a unit of Viacom Inc. "Death at a Funeral," an urban remake of the 2007 British comedy of the same name, opened within industry expectations. The film, produced by Sony Corp's mid-range Screen Gems label for $21 million, skewed to older women, the studio said. "Date Night," a romantic comedy starring Tina Fey and Steve Carell, has earned just over $49 million after 10 days. The 20th Century Fox release also enjoyed a modest drop, of 31 percent. Fox is a unit of News Corp. "Clash of the Titans" fell four places to No. 5 with $15.8 million in its third weekend; the tally for the mythological epic rose to $133 million. The film was released by Warner Bros., a unit of Time Warner Inc.