"There was a saying in my village when I was a girl that love is like wine. Just enough makes happiness. Too much makes a fool. Years after I first heard this, I came to know two such fools."

With those few sentences, the old Italian woman who narrates TNT's "The Engagement Ring" sets the story in motion and establishes the tone of the movie -- a little screwy, a little skewed and greatly amused. Viewers of this two-hour charmer, airing tonight at 8, are likely to find the amusement contagious.

In its own goofy way, this is a family saga. Two immigrant families, the Di Cenzos and the Rosas, long ago established adjacent wineries in the Napa Valley. The young Nick Di Cenzo and Alicia Rosa are passionately drawn to each other, and the two families hope they'll marry.

The flighty, skirt-chasing Nick joins the Army. After winning a diamond ring in a poker game, he impulsively mails it to Alicia, asking for her hand. But the letter is lost in the mail. Alicia later marries her best friend, Johnny, and she and Nick grow to the cusp of old age, each still bitter and angry over the perceived rejection by the other.

Fast-forward 40 years. Sara (Patricia Heaton), the daughter of Alicia (Lainie Kazan) and Johnny (Chuck Shamata), is trying to negotiate the purchase of the Di Cenzo winery to consolidate the family label. She, her stuffy fiance and partner, Brian (David Hunt, Heaton's husband) and Nick's charming nephew, Tony (Vincent Spano), are trying to finesse the animosity of their elders when the decades-old letter, of all things, is delivered, complicating the lives of all.

It's a sturdy premise, and the actors dig into their parts like hungry kids at a lasagna feed. Heaton might not be fully convincing as a daughter to Kazan, but her Sara is an endearing mix of tenderness and feminine strength. Tony Lo Bianco's outraged and intractable Nick is a worthy and funny opponent for Kazan.

And Kazan herself is an erupting mountain of indignation. "I've got a parakeet that's got a little sharp beak," she snarls at Tony Di Cenzo. "Now don't make me get ugly."

And to Sara she bellows, "You know the world is full of land? It's made of it, for God's sakes. I'm sure someplace that doesn't have the Di Cenzo curse on it must be for sale!"

This buoyant and sure-handed film benefits from picturesque wine-country locations and a certain authenticity of spirit. The loves and hates and tensions are nuanced and textured -- these people have a history, and we're always aware of it.

Admirers of the 1987 movie "Moonstruck" might note similarities in character and tone. Although "The Engagement Ring" does not rise to those heights, it has pleasures all its own. There's even the occasional dollop of wisdom, as when one character observes: "You can't control the way people who love you, love you. You just love 'em the best way you can."

There's just the tiniest touch of Christmas toward the end, but chalk up "The Engagement Ring" as a winning holiday surprise.

The Engagement Ring (two hours) airs tonight at 8 on TNT.