Deus ex McKenna

Which is why “St. Vincent” is such a fantastic surprise. Somehow Theodore Melfis concept for the movie made it through the glut of script ideas that presumably clog Murray’s voicemail, and he accepted the firsttime feature filmmaker’s pitch. It’s a perfect fit for Murray, and if his name doesn’t pop up come awards season it will be a crying shame.

It’s not a flattering role for Murray to be sure, or even the most original concept: A vice-ridden Brooklyn washout with a negative bank account and a bevvy of addictions is befriended by his 11-year-old neighbor. You’ve seen this character before. (I’m surprised there’s not been a character named Oscar Bait who fits the profile yet.) Clint Eastwood’s version barked at the kids to stay off his lawn in Detroit. An animated Ed Asner bonded with a Boy Scout in a flying house. And Jack Nicholson won an Academy Award for playing an OCD variation on the theme.

But that’s just what it is, a theme, and like a fine jazz musician who makes a standard his own, Melfi takes some longstanding dramedic tropes — the wiseass misanthrope, the stressed-out single mother, the hooker with a heart of gold — and works them into an original piece that zags when you think it’s going to zig, even if you see where the road is headed.

Time isn’t on the side of Vincent McKenna (Murray), a boozing, gambling, chainsmoking Vietnam vet. His bookie (Terence Howard) is threating his life, his wife’s nursing home is threatening to evict her and even his pregnant Russian prostitute girlfriend (Naomi Watts) is denying him sex until he can pay up. But his horses haven’t been coming in and his bar bill is through the roof —he’s at the end of his rope.

Enter Maggie (Melissa McCarthy) and her 11-year-old pipsqueak son, Oliver (newcomer Jaeden Lieberher), his new next-door neighbors who are insufferably twee — to Vin, at least. The rest of us easily identify with the beleaguered single mother trying to rebuild her life after a devastating divorce and a shy, intelligent middle schooler who’s never known anything but the business end of bullies’ fists. Oliver needs a father figure; Vin needs redemption. See where this is going?

Maybe, maybe not. Although the film suffers from a couple deus ex machina plot contrivances, the characters are fresh enough to keep you from worrying about convention.

McCarthy, who’s become known for her broad comedic chops, downplays Maggie’s dire situation, to great benefit. You see her desperation, but she’s strong enough to avoid warranting your pity. You just pull for her.

And Lieberher kills it as Oliver. With a preternatural emotional intelligence and earnest courtesy, you feel every damaging word — and dodgeball — that slams against his head. He doesn’t so much pull Vin out of his cantankerous, self-destructive shell, as he does hypnotize him through his willingness to take his verbal abuse.

It’s like stone soup for the soul. Oliver pulls a little bit more emotion out of Vin every time they hang out, little by little, until their friendship is a rich, simmering mlange of stories and decidedly not-safe-forkid moments.

If you’ve ever had a shred of love in your heart for Murray, then you owe it to yourself to see “St. Vincent.” It’s almost as if he saves roles like this every 10 years or so; he hasn’t been in this form since 2003’s “Lost in Translation,” and before that he singlehandedly created the existential comedy genre with the genius “Groundhog Day” in 1993.

And Bill: If Ted Melfi ever calls again, please pick up.