She was taking a shower in her cramped lower Manhattan dressing room when Mikhail Baryshnikov burst through the door. She barely had time to turn off the taps and whip on jeans and a T-shirt before the world-famous dancer wrapped her in a passionate bear hug and started twirling her around the room. Baryshnikov's rapturous spinning had been brought on by his delight at Karole Armitage's New York premiere performance, as choreographer and star, of the avant-garde ballet The Watteau Duet. "There was big hugging and kissing," she says, grinning, of that damp embrace 16 months ago. "I heard later he was so excited he drove out with friends to his house in the country and stayed up all night doing imitations of me."

Baryshnikov, the director of the American Ballet Theater, had good reason to be stirred. In a few swift years the slim Armitage has made herself the most sizzling and controversial choreographer in the world of modern dance. Called "the punk princess of the downtown scene" by Vanity Fair, Armitage, 32, is a cult figure in some circles and a loony rebel in others: In Watteau, decked out in black high heels and lacy stockings, she performed cartwheels, rode on another dancer's back and got dragged offstage by her feet. But when Baryshnikov tapped her to choreograph for his company two weeks after he flipped over The Watteau Duet, Armitage scored the biggest breakthrough of her career. It was not her first commission for an established troupe—in July 1984 she composed GV-70 for the Paris Opera's Modern Dance Company—but it was a significant entry into one of the more conservative bastions: With permission of the king, the revolutionary was infiltrating the palace grounds.

Armitage's big moment arrived last May when her oeuvre for Baryshnikov, The Mollino Room, made its New York premiere at the Metropolitan Opera House. As Baryshnikov leapt through the off-beat, off-center moves characteristic of her work, the choreographer, who doesn't dance in this one, waited nervously backstage. Seconds after the gold brocade curtain closed on the exhausted, perspiring company, Armitage, in a strapless black lace prom dress, and Baryshnikov, in blue tights and a T-shirt with grinning fish on it, walked into the limelight to the roars of a startled but enthusiastic audience.

Armitage's ballet, named after Italian architect Carlo Mollino, took two months to compose and was inspired by and tailored for Baryshnikov: She took pains not to score jumps and twists that would land him on his game right knee, damaged in a 1985 accident. She set the three-movement work to music by Paul Hindemith and a record of a Nichols and May routine, My Son the Nurse. She also invited artist David Salle to design the costumes and sets. Salle, a successful New York expressionist, is also her fiancé. The eye-popping designs he came up with featured oversize galoshes, a tea set and a fishing reel.

The public seems to have absorbed all this cutting-edge artsiness just fine. But not, generally, the critics. "A pretentious monstrosity," sniped one. "A cultural con job." Still, Armitage does not lack for supporters. "I liked the piece," says dance critic Robert Greskovic. "Armitage has a fresh, brash talent. Anyway, most new work has a problem being ahead of its time."

No one defends Armitage's work with more assuredness than the choreographer herself. In an idiosyncratic way she has made it her business to free classical ballet from its strict, often rigid postures by using angular, syncopated moves that often seem dangerous. "I think dance ought to be about how it feels to live, not just a machine of beautiful movement," Armitage says. "When you are living in a post-holocaust, nuclear world, I don't think a regal style is appropriate."

Still, Armitage's early training—she put on her first dance shoes when she was 5—was classical. In Lawrence, Kans. where she grew up, she learned plies and jetés from a transplanted New York City Ballet dancer. But after the 1973-74 season in the corps of a Geneva-based Balanchine repertory company, Armitage kicked over the traces. "I felt a little strange in a tutu," she says. "Whenever we were supposed to be flirtatious, coquettish, imperial type girls, I felt silly. The director demanded total submissiveness. The only thing that mattered was perfect technique in a dull way. It was obedience to the rules, rather than great technique that leads to freedom and expressiveness."

Armitage bolted from the classical world and moved to New York to study modern dance. There, living in a walk-up in the East Village, she joined Merce Cunninhgham's troupe and by the late 1970s she was composing her own works, many of them heavily influenced by the punk group the Sex Pistols. "Punk was a little illicit, a little rebellious," she says. "It was about freedom rather than convention and it had a feeling of excitement and danger." In the noisy Drastic Classicism, she leaned back against guitarist Rhys Chatam (then her boyfriend) and flung her legs in the air in wild battements. That year, 1981, she also founded her own company, which now has seven members including herself.

The punk label has been hard to shed. "Punk is over," Armitage says now. "The style was appropriate to the times but the times are no longer that and the style has to change." She and Salle are now working on a collaboration, The Elizabethan Phrasing of the Late Albert Ayler, to premiere in Boston this fall, and she considers it neo-classical; Salle's costumes will be made of lightbulbs. But Armitage still wears a punk Peter Pan crop with bleached blond bangs. "This is a ballerina look," she claims. "It is as close as you can get to a bun without having one."

Her life with Salle, 34, seems as lively as her work. The couple shares his vast Tribeca loft, filled with 1950s Italian furniture. Downstairs, Salle's studio is strewn with giant canvases of Armitage, who often poses for him late at night. Fame hasn't tamed her revolutionary fervor. "Success is really pushing, pushing forward," she says. "Certain people have stakes in what they think dance ought to be and get really upset at what I do. But non-dance people just look at it and enjoy it." Some dance insiders agree with her. "Karole has a confidence that can put people off," says Greskovic. "I think some critics want her to be more humble. They feel that now she's at the Met, she should do something more traditional." They'd better not hold their breath waiting.