LOS ANGELES, Feb 26 (Reuters) - "Moonlight," a drama about a gay black youth coming to terms with his sexuality in an impoverished Miami neighborhood, received the Oscar for best picture on Sunday after a stunning, unprecedented flub in which presenters erroneously announced the musical "La La Land" as the winner.

The cast and creative team for "La La Land" had already taken the stage to begin delivering acceptance speeches when one of the producers interrupted the proceedings to say that the award had been given to the wrong movie, and that "Moonlight" was the real victor. He then held up the envelope to the camera to prove it was true.

Veteran actor-direct Warren Beatty tried to explain that he and Faye Dunaway announced the wrong winner because the envelope they had been handed bore incorrectly the name of best actress winner, Emma Stone, and the movie title "La La Land."

Host Jimmy Kimmel joked after the snafu, "I knew I would screw this show up. I really did."

(Reporting by Steve Gorman; Editing by Sandra Maler and Mary Milliken) ((steve.gorman@thomsonreuters.com; 213-955-6761; Reuters Messaging: steve.gorman.thomsonreuters.com@reuters.net))