The standing ovation shook the Metropolitan Opera on Saturday afternoon, with confetti made from ripped-up programs cascading down from the theater’s highest balcony as a bouquet of pink roses was tossed to the stage. Renée Fleming, the star soprano, had just bid farewell to one of her signature roles — the Marschallin in Richard Strauss’s “Der Rosenkavalier” — closing an important chapter in a storied career that has taken her from opera to far wider fame.

Her final performance as the Marschallin — which was beamed live to cinemas around the world as part of the Met’s popular Live in HD series — came at a moment of transition for Ms. Fleming, 58. In recent years she has been steadily retiring the big prima donna roles and singing more recitals, appearing on Broadway and taking positions behind the scenes, including as a creative consultant at the Lyric Opera of Chicago. Next season she plans to appear as Nettie Fowler in a Broadway production of “Carousel.”

Ms. Fleming says she has no intention of quitting the opera stage altogether: She has expressed an interest in appearing in new operas, and there have been suggestions that she might appear in cameo roles. But her final Met performance as the Marschallin — a married noblewoman with a 17-year-old lover who is learning to come to grips with the passage of time, and at one point sings of rising in the night to stop the clocks — took on special resonance.