Whether or not you could pick Shannon out of a lineup, it would be impossible to walk away from Revolutionary Road without being shaken by his blistering performance as John Givings, a recovering psych-ward patient who might just be the sanest inhabitant of a Connecticut suburb where desperation and malaise seem to be universal conditions.

It’s a role that Shannon, 34, regarded as the ultimate privilege, in part because of his history with the 1961 novel by Richard Yates.

“The first gift my girlfriend ever gave me was the book Revolutionary Road, which is a rather unusual gift to give to your significant other,” he says. “When I say it’s incredible, that really means something because I’m not a very vigorous reader. I usually get about 20 pages in and I get distracted. But this book was like lightning, I couldn’t put it down.”

Shannon, a Kentucky native who began his professional acting career at the Illinois Theatre Center outside Chicago, is hardly some stranger to the big screen who lucked into a part alongside the handsome duo that made Titanic the biggest box-office smash in history, then stole every one of his scenes with them.

Having earned critical acclaim for a supporting role in last year’s Before the Devil Knows You’re Dead and his memorable starring turn in 2006’s Bug, a jarring thriller about a Gulf War veteran convinced his body is infested with microscopic vermin, Shannon is hardly one to be intimidated by the opportunity to perform on the same stage as two of the most widely recognized actors on the planet.

“Leonardo and Kate don’t act like movie stars,” he explains. “They go out of their way to make you feel like you’re on a common ground with them, which is gracious but also intelligent. They make everyone around them feel comfortable enough to give their very best performances, and on top of that, they’re incredibly sweet.”

Now, with Revolutionary Road in theaters and generating him plenty of Oscar buzz – he’s already been nominated for supporting actor honors by the Chicago Film Critics Association and the International Press – Shannon is taking a wait-and-see approach before preparing an acceptance speech.

“It’s like going to an amusement park for the first time,” he says. “It’s exciting, sure. But I’m reluctant to buy into something until it’s actually happening. Let’s just say that if I’m invited to the Oscars, I’ll be sure to RSVP.”