A dazzling Claire Danes took center stage at the London premiere of her aptly titled film, “Stage Beauty,” on Sunday. Wearing a Narciso Rodriguez dress from the designer’s fall 2004 collection, the actress, who mingled with co-star and boyfriend Billy Crudup along with director Richard Eyre, was positively glowing. Maybe it’s the Oscar buzz surrounding the movie, which takes place when men played all the women’s roles in Shakespeare. Danes stars as the 17th-century dresser of Crudup’s character, an actor famous for his Desdemona, whose life is thrown into a tailspin when she’s able to take the stage herself in the role. The film opens stateside in October.