Gwen Verdon would have been a star even if she hadn't married choreographer-director Bob Fosse. Likewise, Broadway's latest great dancer, Ann Reinking, who was Fosse's protégée and lover for six years. "She would have done it without me," says Fosse, "but I helped her move faster." That's fair, and indeed, now that they've split, Reinking's speed is dazzling. She's the star of Bob's current Broadway smash, Dancin', which was created to be an ensemble show without a star. "No one was supposed to emerge," says Reinking, 27, "but it seems I have." This week she's exploiting it with a postcurtain one-woman midnight cabaret act at the Grand Finale. And for the first time Reinking is believable when she says she's glad she lost out in the casting semifinals of TV's Charlie's Angels and Three's Company.

How does she handle eight Broadway performances and six club shows in a week? "Success really gives you energy," says Ann. Yet often the spirit is willing, but the flesh objects. "Sometimes I lie in bed at night and twitch," she admits. "The tension is coming out of me. It's like Mexican jumping beans."

Ann arrived in Manhattan 10 years ago from her native Seattle. She settled into a YWCA and, though she continued her classical study at the American Ballet Theatre School, joined the corps de ballet of the Radio City Music Hall. Mostly she became known for pranks. (While her back was turned to the audience she would squirt her partner with a water pistol.) "It wasn't a great ballet company," she notes. Three months later Ann was touring with Fiddler on the Roof. Since then she has performed in eight productions on Broadway, winning Tony nominations in Goodtime Charley and Dancin' and making her name pinch-hitting for such leading ladies as Donna McKechnie in A Chorus Line and Verdon in Chicago. "It was good for my career," she says, "but I wouldn't do it now because you can get the reputation of being everybody's replacement. It's more fun to be the original."

When she met Fosse, her brief marriage to singer Larry Small had ended, and Bob was separated from third wife Verdon. "He's everything to me," says Ann. But they finally broke up during the Boston tryout of Dancin'. "There was no scandal," she claims. "We had to commit more, or part as good friends. It still bothers me to see him with other women." Fosse is now squiring Jessica (King Kong) Lange.

Reinking shares a Manhattan apartment with Charles Ward, 25, a member of the Dancin' company, her poodle, Christian, and his cat, Narcissus (or "Narc" for short). Already in her career Reinking has sprained ankles, torn hamstrings, been dropped on her head and fractured her back. "A ballerina gets more injuries than a star quarterback," she observes. "A dancer's life is young." So her future, she's decided, is in Hollywood. "Once a play is over, all you have left is the memory and some Playbills," she says. "But in movies you get your best take in and it's there for life." She makes her screen debut opposite George C. Scott in Movie, Movie, a nutcake comedy due in October. And she fantasizes about bypassing TV altogether and co-starring with the legends. "If I knew nothing bad would happen," she laughs, "I'd love to act with Marlon Brando. But I know I'd be the one to get hurt."