On Sunday afternoon at the David H. Koch Theater, the ballerina Darci Kistler made her farewell to dancing onstage. Some in the audience remembered how she first burst into their lives 30 years before, when she danced the Swan Queen with the School of American Ballet. I cannot forget that when she joined New York City Ballet that same year, she already danced not like a flower in bud but like a full-blown rose, in her first solo role as a professional dancer. The company danced in Paris in September 1980, and she performed the Scherzo in Balanchine's 'Tchaikovsky Suite No. 3.' To choreography that had seemed among the master's least distinguished, she brought an easy hugeness of scale and a sparkling rapture that were intoxicating. Surely not since the 1930s had a performer so youthful arrived on the scene with a dance character so fully formed. In November 1980 in New York, Kistler made her debut in the second movement of Balanchine's 'Symphony in C,' one of the great ballerina roles. To find such a combination of sweep and sweetness was startling. She had fearlessness, wit, delicacy, expansiveness and an irrepressible love of dancing. Her long, tapering limbs; remarkable breadth of shoulder; loveliness of facial features (and in particular her lips, whose beautiful outline registered in the theater with great distinction); the beautiful pliancy of her feet: All these aspects were already apparent. There are tales of how Balanchine was delighted by her rhythmic freedom as she reaccentuated passages of old choreography and thereby rejuvenated them. When she appeared again in 'Symphony in C,' 15 months after her debut, I marveled at how much more contrast she then found in it. Jerome Robbins adored her dancing, too. In the first performances of his 'Gershwin Piano Concerto' (1982), she ate up space in a series of turns. But though Balanchine's remaining time was short (he died in 1983), hers was shorter. Before she had been with the company two years, a severe ankle injury occurred and kept her offstage for years. Only in 1987-90 did she start again to reconquer the ballerina repertory and acquire further roles. Though she never danced with the same easy attack again, her delight in dance did not fail, and her sensitivity and dance intelligence kept growing. And, most valuable of all, the freedom of her musicality remained, lighting up the Balanchine repertory. In one physical respect, she had become only more remarkable: her hair. There are Balanchine and Robbins roles where the ballerina dances with loose hair, and Kistler's now reached her hips: a fair, voluminous cascade. When she sped across the stage in a series of turns in 'Walpurgisnacht,' her face now invisible beneath the released locks, this mane became a traveling vortex. The film 'George Balanchine's 'The Nutcracker,'' in which she appeared as the Sugar Plum Fairy, suggests that her glory lasted until at least 1993. But my memory is that by 1992, her dancing had become scaled down, polite and musically safe. Since then her career has been a long, slow fade. She has retired at age 46. The sweetness of her presence remains. Sunday's performance began with Balanchine's pair of Stravinsky ballets, 'Monumentum pro Gesualdo' and 'Movements for Piano and Orchestra.' The most affecting moments came from the turn of her head, now to her partner, now to the audience, now to the wide space before her. The light still falls beautifully on the planes of her face. After the first intermission, she returned as Titania in Balanchine's 'Midsummer Night's Dream,' dancing the Nocturne scene when the fairy queen becomes enamored of Bottom in his ass's disguise. Titania had been one of her earliest roles, and, again, her sweetness of manner made its old impression. The company then performed 'Danses Concertantes,' the ballet whose 1989 revival she had so distinguished. Finally, after the second intermission, she danced the final act of the production of 'Swan Lake' by her husband, Peter Martins. She thus returned to the Swan Queen role she had danced with the School of American Ballet -- that was the one-act Balanchine version of 'Swan Lake,' in which the master coached her -- and giving us a swan song, too. Who is to judge the twilight of a ballerina? My life was changed by the 56-year-old Margot Fonteyn, but there were people who could not bear to see her dancing anymore, just because it had once meant so much to them. This season I have seen momentary glimmers of what I once loved -- the twinkle of Kistler's feet to the music in some lifts in Martins' 'Morgen,' and her poise and line in his 'Thou Swell.' After Sunday's performance I had coffee with a ballet-goer who had become a devotee of New York City Ballet in 1996. I was hoping that he might tell me how the later Kistler, now 46, had meant to him something of what Fonteyn once meant to me. But in all those years, Kistler's dancing had never been one of his reasons to follow the company. Others must have taken more from it, but her autumn has lasted far longer than her spring and summer combined, and I cannot see that since 1992 she has been a good role model for the young. Her solo dancing in the Stravinsky ballets was wretched, flicking lightly at steps that require a rigor she lost long ago. At curtain calls, sweetness was all. Her partners that afternoon --Charles Askegard ('Monumentum'), Sebastien Marcovici ('Movements'), Henry Seth ('Midsummer' and, in 'Swan Lake,' Rothbart) and Jared Angle (her 'Swan Lake' prince) -- brought her flowers, embraces, laughter. The excellent conductor (Clotilde Otranto), Kistler's former partners, other dancers, her husband, her daughter and three of her brothers were among those who joined her onstage. Confetti fell in showers. With the retirement of this last Balanchine ballerina, we have all moved one generation on in history. 