A wicked, sexy and ultimately devastating study of a young dancer’s all-consuming ambition, “Black Swan” serves as a fascinating complement to Darren Aronofsky‘s “The Wrestler,” trading the grungy world of a broken-down fighter for the more upscale but no less brutal sphere of professional ballet. Centerstage stands Natalie Portman, whose courageous turn lays bare the myriad insecurities genuinely dedicated performers face when testing their limits, revealing shades of the actress never before seen on film. As with “The Wrestler,” Fox Searchlight faces formidable marketing challenges, likely exploiting the psychosexual thriller’s racier elements to eke out a similarly modest score.

Once again, Aronofsky is drawn to the irresistible force that drives certain personality types to chase the spotlight, except in this case, the impulse doesn’t seem born of some deep-seated egotism, but is simply programmed from childhood by a controlling mother (a creepy but far from one-note Barbara Hershey). Portman plays Nina, a virginal young ballerina who comes across as an incomplete soul, her single-minded interest in dance eclipsing all other aspects of her being.

In the film’s staggering opening sequence (arresting enough to give skeptical male auds reason to stick around), Nina dreams of herself in “Swan Lake’s” lead role, circled by dark forces. But in order to land the Swan Queen part in Lincoln Center’s upcoming season of reimagined classics, Nina must also master the show’s seductive Black Swan. The svengali-like figure responsible for her corruption is French ballet maestro Thomas Leroy (played with smoldering physicality by Vincent Cassel), a director already ensnared with his previous star, Beth MacIntyre (Winona Ryder in a crucial but barely-there part).

Brief glimpses of Beth on her way out remind how quickly young replacements are cast aside in the cruel world of ballet, though Nina is no Eve Harrington. What’s missing from Portman’s characterization —  and the film itself —  is the pressing need to perform, the inescapable artistic contagion that powered Powell and Pressburger’s “The Red Shoes” (“Black Swan” sorely lacks that film’s romantic dimension as well). Instead, Portman’s naive young dancer is driven by a need for perfection at all costs, a variation on the impossible obsession that destroyed the protagonist in Aronofsky’s “Pi.”

From the beginning, Thomas remarks on Nina’s ability to nail the technical requirements of the role, while questioning whether she can loosen up enough to capture what the Black Swan demands. Ironically, the metamorphosis is well within Portman’s grasp as a performer (as is the ballet, which the actress studied intensively for 10 months prior to shooting), while the effort to embody the frigid young ingenue seems to pose the greater challenge.

Aronofsky and costume designer Amy Westcott are none too subtle with the film’s symbolism, dressing Nina in innocent white outfits while those around her wear darker and considerably more ominous colors. These exaggerated stylistic choices (somewhat at odds with Aronofsky’s documentary-like sense of detail and Matthew Libatique’s handheld shooting style) extend to the production design as well, adding yet another motif: Reflective surfaces, mostly mirrors, offer fleeting glimpses of Nina’s other half.

Coupled with Clint Mansell’s score, which expands upon Tchaikovsky’s original “Swan Lake” compositions to suggest something considerably more macabre (further aided by proper horror-movie sound design), the result is an unsettling yet ultimately intuitive blend of classical and contempo techniques.

While Thomas tries to draw Nina out, and her suffocating stage mother attempts to freeze the growing rift in her daughter’s personality, the individual who reveals Nina most is Lily (Mila Kunis), a new addition to the ballet company who serves as her dark double. Lily is spontaneous, seductive and experienced in a way Nina is not, making the latter fiercely jealous of what comes so naturally to her rival —  a problem that can only be overcome by breaking down certain boundaries between them.

Already the film has acquired a certain lesbian allure, courtesy of a trailer that somewhat unfairly teases a scandalous Portman-Kunis love scene. This footage will no doubt help to entice ballet-averse auds, though “Black Swan” is anything but a Brian De Palma-style erotic escapade (superficial echoes of “Sisters” and “Femme Fatale” notwithstanding).

Aronofsky seems to be operating more in the vein of early Roman Polanski or David Cronenberg at his most operatic. Though the director never immerses us as deeply inside Portman’s head as he did Mickey Rourke’s in “The Wrestler,” the latter third of “Black Swan” depicts a highly subjective view of events that calls to mind the psychological disintegration of both “Repulsion” and “Rosemary’s Baby.”

At first, Nina’s hysteria seems innocuous enough, exaggerating minor injuries (a split toenail or irritated shoulder rash) into squirm-inducing conditions, or having her project a dark version of herself onto strangers glimpsed in the subway or on the street. But as the pressure intensifies, Nina’s hallucinations begin to take over, to the extent that nearly everything can be read as manifestations of her subconscious —  the spiritual cost of trespassing beyond her comfort zone for the sake of a role.