The mistake -- only corrected after the producers of "La La Land" had come on stage to accept the award -- was a stunning end to the film industry's biggest night.
Hollywood legends Warren Beatty and Faye Dunaway were entrusted with the task of announcing the best picture award.
After scrutinizing the card for some time, they handed the award to "La La Land."
But the mistake was soon realised, and the team from "Moonlight" came to accept their statuette.
"La La Land" ended the night with six awards, to three for "Moonlight."