'Moonlight' Wins Best Picture After Huge Oscars Screwup

Warren Beatty and Faye Dunaway pulled a Steve Harvey -- announcing "La La Land" won Best Picture, when it was really supposed to go to "Moonlight" ... and the fallout was hysterical.

In the greatest Oscars ending ever ... Warren and Faye called the 'La La' crew up onstage -- and they were several minutes into their acceptance speeches before someone figured out the massive screwup.

If you missed it you gotta see how it played out -- stage managers looked like Keystone Cops running around onstage. To their credit, the 'La La' folks graciously handed over their Oscars when the "Moonlight" cast and crew came up.

As for what went wrong? Watch ... Warren's explanation is an instant Hollywood classic, but basically he and Faye were handed the wrong card -- the one for Emma Stone's Best Actress win ... which had been handed out just before Best Picture.

Price Waterhouse just explained the obvious ... "The presenters had mistakenly been given the wrong category envelope and when discovered, was immediately corrected." Truth be told, not immediately. Also, why were there 2 "Best Actress" cards?

And get this -- Leo DiCaprio might be unwittingly involved! Best we can tell ... he walked off the stage holding Emma's envelope after her acceptance speech. We don't know what happened backstage, but somehow that card -- or a duplicate of it -- ended up in Warren and Faye's hands.

You are not alone, Steve Harvey.