The 39th Annual Telluride Film Festival officially gets underway tonight. But the fest provided a “sneak preview” of its highest profile movie: director/star Ben Affleck‘s pulse-pounding true life thriller, Argo, which made its world debut this afternoon for patron and sponsor passholders and selected press. Although not announced as an official part of the Telluride lineup, it was strongly tipped to come here and Affleck introduced today’s screening: “You are the first paying people to see the film. I know you didn’t literally pay, but in my heart you did. This is actually one of the few film festivals that really is about seeing movies instead of just walking around and talking about them.” Judging from the reaction during the end credits as well as talk on the streets afterward, Warner Bros and Affleck not only have a hit but a slam-dunk major Oscar contender in several categories. At last February’s Oscars Governors Ball, this film was still in post. But a top Warners exec predicted to me that it could be the studio’s best shot at top Oscar attention in 2012. Looks like that bold prediction was right.

Jump-starting the long 6-month awards season, which officially begins with the Venice/Telluride/Toronto film festivals, this supremely well-crafted studio film is the kind that Academy members (and there were several on hand for this screening) eat up. “It’s got my vote as one of the 10,” a voter told me after the screening. It also shows the movie industry in a favorable light, which should further impress Oscar voters. So, unless I am crazy, expect nominations for picture (producers are Affleck, George Clooney, and Grant Heslov), director for Affleck, screenplay For Chris Terrio, and supporting actor for Alan Arkin and possibly Bryan Cranston. Affleck also could figure in the crowded actor contest. Other possibilities are editing, score (Alexandre Desplat), and Rodrigo Prieto’s stirring cinematography.

Related: Hot Trailer: Ben Affleck’s ‘Argo’

Telluride has a recent tradition of debuting at least one solid Best Picture contender. Recent winners Slumdog Millionaire, The King’s Speech, and The Artist all started their awards season right here in the Rockies. And Argo has already laid claim to one of those spots if reaction holds. Next stop is Toronto a week from today, where Argo should be huge because of its strong Canadian connection. It’s the story of the 6 Americans who managed to escape and find refuge in the home of the Canadian ambassador after 52 of their U.S. Embassy colleagues were taken hostage by Iranian militants in Tehran in 1979. The incredible story was kept secret until President Clinton declassified it in 1997.

Affleck plays a CIA exfiltration specialist named Tony Mendez who tried to plan a rescue under the ruse of making a fake Hollywood science-fiction film called Argo. Although the filmmakers have taken some dramatic liberties to tell it, this true story is powerful stuff. The film not only works as a suspense thriller, it also has strong comedic elements thanks to the Hollywood angle. Especially with the jaded producer played by Arkin (“If I am going to make a fake movie, it better be a fake hit!”). John Goodman plays Oscar-winning makeup artist John Chambers who had a key role in setting up the ruse for Mendez who I’m told will be attending the Toronto premiere.

Former President Jimmy Carter even has a part through a new audio interview which the film’s producers taped with him and used over the end credits, giving the film extra credibility. After the screening, executive producer Chay Carter (no relation) told me they were given only 30 minutes deadline to get it done. It was well worth it.

It’s also a wise move for Warners to hit the fest trail with this to build anticipation for the October 12th wide release and give cred to the subsequent awards campaign. I am told the studio, knowing it has a long road to go and lots of competition (even from themselves), is going to take it slow in crafting a campaign for the long haul for the movie and Affleck. After strong critical and public reaction to his first two directorial efforts, Gone Baby Gone and The Town, the star and Oscar-winning screenwriter (Good Will Hunting) has emerged as a major directing talent and seems to be fashioning a career in the tradition of Clint Eastwood. Both his previous films were shot in his hometown of Boston, so Argo is a definite leap out of his backyard. The first Telluride audience was clearly impressed. And so the season really gets going.