The African American coming-of-age drama "Moonlight" won best picture at the 89th Academy Awards Sunday - but only after Hollywood's top prize was mistakenly awarded to "La la Land."Onstage to present the award, Warren Beatty and Faye Dunaway opened the envelope and announced "La La Land" was the winner. The film's producers were already giving their acceptance speeches when they were interrupted by the news that "Moonlight" had actually won the award.A chagrined Beatty blamed the flub on the envelope, which he said contained a duplicate of the card for the best actress trophy - awarded to Emma Stone for "La La Land."The best picture win was the third of the night for "Moonlight," which also won best supporting actor for Mahershala Ali and best adapted screenplay for director Barry Jenkins and Tarell Alvin McCraney."La La Land," director Damien Chazelle's acclaimed story of struggling artists in love, won six Oscars.