This is one of the most legendary unscripted moments in Oscars history!
At the 49th Academy Awards in 1977. Sylvester Stallone was on stage at the podium to present the award for Best Supporting Actress.
He was riding high on the massive success of Rocky, which was nominated for 10 awards that night.
As Stallone started speaking, Muhammad Ali quietly snuck up right behind him in a classic tuxedo.