“St. Vincent” opens Friday at Point, Eastgate, Star Cinema and Sundance. Pg-13, 1:36, three stars out of four.

“St. Vincent’ has a great, juicy role for Bill Murray, who despite being one of the most beloved creatures walking this earth seems to rarely find roles to fit his talents. Either he does a small but memorable cameo in a film like “Zombieland” or a Wes Anderson joint, or he takes a lead role that seems to deliberately suppress his charm and wile (“Hyde Park on Hudson”).

But he’s got Vincent McKenna by the tale in Theodore Melfi’s “St. Vincent.” “Vin” to his friends (which are a small and dwindling bunch indeed) is an abrasive, alcoholic old New Yorker who stumbles through life with a “So’s your muddah!” attitude, snarling at the barkeep who cuts him off, falling down drunk in his shabby little house. He’s very Old New York — I could just see this guy woozily standing up at a zoning board meeting to protest a new condo development or something. Murray plays him perfectly, a wreck of a man who still has a certain fire in those blue Murray eyes.

It’s a great character, but writer-director Melfi doesn’t build a great movie around him. “St. Vincent” is a comedy-drama that lunges for both comedy and drama when it should be following Murray’s lead and just play it cool and close to the vest. It has a serious but not fatal case of the cutes, but Murray very nearly saves it, finding the truth in Vincent in even the most maudlin turns.

Vincent has new neighbors, single mother Maggie (Melissa McCarthy) and her 12-year-old son Oliver (Jaeden Lieberher). Reluctantly, because he needs the money, Vincent agrees to babysit Oliver after school, which means taking Oliver along on his adventures, which includes jaunts to the local bar and race track. Along the way, he teaches Oliver how to fight back against class bullies and how to bet the trifecta — essentially skills for any sixth-grader.

Oliver also quickly learns that Vincent’s crusty exterior is about an inch deep, and that’s a good-hearted guy who visits a mysterious woman at a nursing home every week, and is helping a Russian prostitute (Naomi Watts) he frequents with her pregnancy. Murray makes Vincent’s seeming contradictions makes sense, as he seems to need to hide his good heart from the wider world.

“St. Vincent” is at its best when we just get to hang with these characters, especially Murray and Lieberher, who have great chemistry tooling around Brooklyn in Vincent’s old “woodie,” the boy’s quiet watchfulness a nice counterpoint to the old man’s bluster. McCarthy is also wonderful in a more straightforward role than the likes of “Tammy” or “The Heat,” showing the travails a working mother goes through simply and honestly. Chris O’Dowd also has a nice turn as Oliver’s Catholic school teacher, surprisingly welcoming of all faiths into his classroom, but proclaims that Catholicism “is the best religion, because it has the most rules.”

Watts is fun but seems like one character too many for this ensemble, and that’s the essential trouble with “St. Vincent.” It seems overstuffed with stuff — subplots and extra characters and dramatic moments turned up just two spots too loud. Still, the charm of Murray and the ensemble cast generally triumph over the schmaltz.