Isabelle Huppert commits wholeheartedly to every bonkers moment in “Greta,” and that’s what makes the movie thrilling.

Neil Jordan’s “Single White Female”/“Fatal Attraction”-ish horror movie is old-fashioned in a way that’s surprisingly pleasing. When we’re supposed to be scared of something, for instance, rumbly, ominous chords pop up on the soundtrack. There’s a horrifying scene that — say it with me — turns out to be a dream. A woman who fears there is an intruder in her home walks around with the lights off, as if the last 50 years of someone-waiting-in-the-dark-of-your-apartment-with-a-knife movies never happened.

The premise is simple. Huppert is Greta, a New Yorker who’s lonely because her husband is dead and her daughter is studying abroad. She leaves her purse on the subway, where it’s found by Frances (Chloë Grace Moretz), who is in the market for a mother figure because her mom just died. The two become friends when Frances returns the purse, but then she’s creeped out when she finds a cache of identical purses in Greta’s home, suggesting that Greta deliberately sought her out. Frances tries to end the relationship, but Greta continues to stalk and harass her young friend.

The character of Greta fits Huppert as perfectly as a Chanel suit. Indeed, it has been tailored for the veteran actress, an Oscar nominee two years ago for the similarly twisted “Elle.” Greta claims to be from France, but it turns out she’s faking it, which is a sly in-joke because Huppert is as French as they come. Greta is a gifted pianist who tries to teach Frances to play, a nod to Huppert’s correspondingly inclined title character in “The Piano Teacher.” And there’s a final visual punchline, having to do with the Eiffel Tower, that puts a capper on the movie’s madness.

Jordan makes excellent use of the placidity of Huppert’s face, which is in marked contrast to Greta’s increasingly frantic behavior. Huppert’s understated wit makes her an ideal villain (if only the James Bond producers would take note), whether she’s tossing off the line, “I get by one way or another” when Frances comments that Greta must miss her daughter or assuming a blank look of innocence when Greta is confronted with the depths of her evil.

Huppert has evident sympathy for Greta’s pain, and, for most of the movie, so do we. But then comes a spectacular scene, set in the restaurant where Frances works, when Greta finally gives up on keeping her emotions under wraps and Huppert unleashes a “Real Housewives of New Jersey”-style table flip while Vivaldi’s “Four Seasons” hits a crescendo behind her. It’s thrilling.

If only everything in the movie shared Huppert’s confidence and brio. The movie flips the usual Hollywood script so that it’s only the women who get to play compelling characters, but that makes it kind of sad watching fine actors Stephen Rea and Colm Feore flounder in dopey roles. Even Moretz, who can be wickedly funny, is somewhat bland as Frances.

Speaking of Frances, it can’t be a coincidence that her name is one letter away from France, the country the movie has so much fun pretending it has nothing to do with. In fact, throughout my typing of this review, I have consistently mis-typed the name of the other main character, Greta, as “Great.” Or maybe my fingers knew exactly what they were doing, because when Huppert sinks her teeth into a role, the results are almost always great.