Bill Murray ambles down a Brooklyn street in a “catch of the day” t-shirt emblazoned with a pin up girl, camouflage cargo shorts and old school over-ear headphones as Vietnam War veteran Vincent, the eponymous star of first time writer/director Theodore Melfi’s St. Vincent.

Within the film’s first few minutes, Vincent is established as a gambling drunk who has a codependent relationship with a pregnant Russian stripper named Daka (Naomi Watts) and a soft spot for Golden Girls. He’s also fond of playing fast and loose with the truth. Upon meeting his new neighbors – single mother Maggie (Melissa McCarthy) and her young son Oliver (Jaeden Lieberher) – he blames Maggie’s moving company for destroying his fence, which he’d actually demolished the night before while pulling into his driveway in a drunken stupor.

Vincent’s dilapidated, hedonistic lifestyle is soon interrupted when Oliver winds up at his doorstep, having lost his house keys and cell phone in a tussle with bullies at his new school and unable to get into his home or call his mother. When Vincent asks him why he let the bullies get away with the abuse, Oliver says, “I’m small if you haven’t noticed,” to which Vincent retorts, “So was Hitler.” Oliver notes that’s a “horrible comparison,” but ultimately settles into Vincent’s rundown abode, petting his large, white Persian cat and chowing down on some homemade sushi (sardines on saltines).

Melfi develops the relationship between Vincent and Oliver as two disparate souls connected by loneliness and their inherent peculiarities. Begrudgingly, Vincent takes pity upon the slight and sensitive Oliver, while Oliver in turn makes allowances for Vincent’s less savory antics and ultimately ends up relishing partaking in some, taking a liking to the race track, even helping Vincent land a trifecta. The dynamic between Vincent and Oliver isn't one between an old sage and a young sponge; their relationship is one of equals.

Murray’s affable performance, imbued with his sad and sympathetic eyes, is understated and heartfelt. There’s never a moment, even in his character’s most irresponsible moments, that the pain of the person isn’t apparent, that the conflict between wanting to be a hardened curmudgeon and his innate generosity isn’t obvious. Lieberher’s Oliver never becomes the caricature of the awkward only child of a single mom, managing to always exude a certain degree of strength, resilience and compassion where his war vet friend is concerned. It’s Oliver’s ability to accept Vincent as a full person, one with varied experiences that make him who he is, a person who has a wealth of goodness within him despite his many offenses that allows him to discover Vincent's saintliness.

While Murray’s performance was expectedly brilliant and up-and-comer Lieberher was refreshingly authentic in his role, McCarthy’s understated turn as Maggie often made her a scene-stealer. After a slew of movies in which her size became a focal point of her jokes as well as crudeness and an insatiable sex drive, McCarthy was allowed to couple her impeccable comic timing with tenderness. She was a bit more Sukie St. James (Gilmore Girls) and a little less Megan (Bridesmaids)-Diana (Identity Thief)-Mullins (The Heat)-Tammy.

Melfi’s taut, affecting and genuinely funny film deserves all the plaudits it’s bound to receive. On paper, St. Vincent had all the makings of another sap-fest, a coming-of-age story of sorts where a wisened, crooked crank finds new life with the help of a virtuously naïve child. But, St. Vincent is far from the insipid movie it threatened to become. It’s less a movie about a contrived evolution, and more about a necessary unraveling.