Lionsgate and Twisted Pictures’ “Saw IV” easily slaughtered the competition at the weekend domestic box office, becoming the highest opener of the troubled fall and upsetting conventional wisdom that hardcore horror no longer works.

“Saw IV” grossed an estimated $32.1 million from 3,183 locations, just shy of the $33.6 million domestic opening of “Saw III” but ahead of the $31.7 million opening of “Saw II,” according to Rentrak. It gives Lionsgate its third film of the fall to come in No. 1 after “3:10 to Yuma” and Tyler Perry’s “Why Did I Get Married?”

The second headline of the weekend was Disney’s offbeat dramedy “Dan in Real Life,” toplining Steve Carell and directed by Peter Hedges. Film, produced by Jonathan Shestack, proved a welcome antidote to the flood of serious fall dramas, opening at an estimated $12 million from 1,921 theaters and coming in at No. 2. Pierce Gardner and Hedges penned the script, while Juliette Binoche and Dane Cook also star.

“It is counter to everything that is in the marketplace. People love to get lost and laugh,” Disney distribution prexy Chuck Viane said.

Disney said that teens made up nearly 20% of the aud.

Overall, the domestic box office remained down over last year for the sixth weekend in a row, although the gap was narrowed substantially. Weekend was down only 1% compared with the same frame last year, when “Saw III” led.

Thanks to the boffo summer, biz is still running 7% ahead of 2006 year to date, according to Nielsen EDI. However, fall-to-date biz is down by 6%. Many attribute the recent downturn to a glut of serious-minded or political dramas that auds seem to be rejecting, opting for lighter fare. That’s making for an interesting — and wide open — awards season, at least so far.

One awards contender doing solid box office biz is Warner Bros. George Clooney starrer “Michael Clayton,” which declined 25% this weekend to an estimated $5 million from 2,585 runs for a cume of $28.8 million in its third weekend in wide release. Drama, which posted a per-screen average of $1,946, placed No. 6.

Miramax’s “Gone Baby Gone,” directed by Ben Affleck, is also showing strength, coming in No. 7 for the frame. Film declined 29% in its soph sesh to an estimated $3.9 million from 1,713 runs for a per-screen average of $2,277 and a cume of $11.2 million.

Other awards contenders in wide release weren’t so lucky. DreamWorks-Paramount’s Halle Berry-Benicio Del Toro starrer “Things We Lost in the Fire” continued to struggle, declining 55% in its second frame to an estimated $715,000 from 1,142 runs for a cume of $2.8 million. Pic placed No. 20.

New Line’s holdover “Rendition,” set against the backdrop of the war on terror, missed the top 10 list in its second frame, placing No. 11. Film declined 42% to an estimated $4.1 million from 2,782 theaters for a cume of $9.5 million. Film placed No. 11.

Despite plenty of proclamations earlier in that year that moviegoers were tiring of horror, it is a genre that has more than held its own this fall. The opening number for “Saw IV” far outpaced the $22.9 million debut of “The Game Plan,” previously the best opener of the season. “Saw IV” also saw stellar overseas numbers as it rolled out in its first round of territories.

With the bow of “Saw IV,” the “Saw” franchise is poised to cross the $500 million mark at the worldwide box office this week.

“Horror is still alive and well. ‘Saw’ fans have proven their loyalty to the franchise once again by giving it the biggest opening of the fall season,” Lionsgate prexy of distribution Steve Rothenberg said.

Pic was directed by Darren Lynn Bousman and returns Tobin Bell to the role of Jigsaw. “Saw II” grossed $55.2 million domestically, while “Saw III” grossed $87 million.

Exit polls showed that 90% of the “Saw IV” aud had seen all the films in the franchise. Of the aud, 52% were female and 48% were male, repping a 3% bump in female turnout.

The weekend before, Sony’s vampire horror entry “30 Days of Night” came in No. 1.

As expected, “Saw IV” sucked some of the life out of “30 Days” over the weekend, although the Sony title still came in at No. 3. “30 Days” declined 58% in its soph sesh to an estimated $6.7 million from 2,859 locations for a cume of $27.3 million.

Lionsgate’s “Why Did I Get Married?” continued to play strongly as well, coming in at No. 5 in its third frame. Romantic laffer declined 53% to $5.7 million for a cume of $47.3 million.

Disney had three titles in the top 10 — “Dan” and holdovers “Game Plan,” which came in No. 4 in its fifth frame, and “Tim Burton’s Nightmare Before Christmas in Disney 3-D,” which placed No. 10 in its second frame.

“Game Plan” declined just 23% to $6.2 million from 3,342 screens for a cume of $77 million, the highest-grossing film of the fall.

Fox Atomic’s sports spoof “The Comebacks” came in at No. 8, declining 38% in its second frame to an estimated $3.45 million from 2,812 locations for a cume of $10 million.

Sony’s Joaquin Phoenix-Mark Wahlberg starrer “We Own the Night” placed No. 9. Crime drama declined an estimated 37% in its third frame to $3.4 million from 2,402 locations for a cume of $25 million.

Playing in only 564 locations, Disney’s annual holiday entry “Nightmare Before Christmas” declined 37% in its second frame to an estimated $3.3 million for a cume of $10 million.