Basil Rathbone in "The Adventures of Sherlock Holmes" (1939). Part of the restored collection of Rathbone as Sherlock movies we're watching.
Per a write up: "Despite his appearing only twice in Doyle's original stories, later adaptations and pastiches have often given Moriarty greater prominence and treated him as Sherlock Holmes' archenemy."
Sherlock and Moriarty traded blows in this one. Moriarty develops a very, very clever ruse to cause Sherlock to discredit himself. Sherlock "bites".
Near the beginning of the movie, Moriarty clearly says to Sherlock's face that Sherlock is his archenemy. Moriarty said to Sherlock he was tired of crime and would rather be a Scientist -- but only after Sherlock was dealt with. Thus, in the film, Moriarty's primary goal was to totally discredit Sherlock -- so that Moriarty could retire from crime as the winner.
