Rudolf Nureyev could make one believe in biorhythms. Last Wednesday in the Zurich Ballet's "Manfred," Nureyev's dancing was strained and stiff, but Saturday night, dancing in his own "Don Quixote" at Kennedy Center's Opera House, he was much more relaxed and fully in control of both the production and the audience.

No, he didn't dance like a 20-year-old. His jumps were shaky, his turns sometimes beautifully smooth, sometimes eccentric. But beaten steps and footwork were precisely executed throughout the evening. His performance was so generous that technique didn't matter. Nureyev was obviously having a grand time as Basil, the barber who woos and wins Kitri, an innkeeper's daughter, in this balleticized subplot of Cervantes' great novel, and his stage magic was so potent that he could make the audience believe anything he wanted.

In many respects, his performance was grandly outrageous. He conducted the conductor (Andre' Presser, who good-humoredly abetted him throughout the evening while coaxing as much as possible out of the Minkus score); held balances longer than musical phrase or choreography intended; stalked around the stage, milking the palpable silence that had fallen over the audience during the third act grand pas de deux; camped and hammed through many of the mimed passages; and let the audience know exactly how difficult his accomplishments were, and how much fun he was having. Nureyev and the audience thanked each other profusely during bows and curtain calls throughout the evening.

Such goings-on would be reprehensible in another ballet. But "Don Quixote" has never been regarded as sacrosanct in the West, and all of Nureyev's shenanigans could legitimately be considered part of Basil's character as well as his own.

Kitri was danced by guest artist Yoko Morishita, a tiny, delicate ballerina whose balances are phenomenal and whose fouette's in the third act pas de deux were absolutely perfect. If anyone can be spirited and subdued at the same time, Morishita accomplished it. Her performance was warmer than the perfect, porcelain-doll interpretations she delivered several years ago, but her projection would have been too subtle even had Nureyev's been less broad.

This production of "Don Quixote" suits the Zurich Ballet admirably. It's a small company ( fewer than 40 dancers); too small, really, to do justice to the 19th-century Russian classics. Twelve dryads rather than two or three times as many make the don's dream scene look thin. But in the character dances, particularly the last act's Fandango, the company danced wonderfully. They made lusty gypsies and danced with zest throughout.

As a whole, the production is less busy than most of Nureyev's stagings of the classics. The pacing of the ballet, however, was so frantic that the story threatened to get lost. More breathing room would have helped mime scenes register more fully, particularly where Basil feigns suicide and the don forces Kitri's father to let the couple marry before the bridegroom dies. Nicholas Georgiadis' costumes and sets are glorious. He errs only once, in giving the monsters in the don's dream tattered umbrellas and helmets cut like tin cans, making them look like futuristic bums.

The supporting roles were, for the most part, well danced. Deborah Dobson danced the famous Queen of the Dryad variation smoothly and graciously. Gerard Ebitz danced the role of Espada the toreador well, but handled his cape as though it were a wet beach towel. Kay Preston was superb as the Streetdancer; Jonas Kage was a spirited Gypsy; and Janet Popeleski displayed astounding elevation as both Amor and an intrusive character christened the First Bridesmaid. Best of all was Maciej Miedzinski's vain, mincing, totally foolish Gamache, the man Kitri's father wanted her to marry. Rudolf Budavary emphasized the more loathsome aspects of Sancho Panza's character rather than the lovable ones, and Robert Wayne Rudd's Don Quixote was insipid and vague.