Some operas are based on plays. For example, Shakespeare's Othello was the source for Rossini's Otello (1816) and Verdi's Otello (1887). Romeo and Juliet inspired Berlioz's Roméo et Juliette (1839) and Gounod's Roméo et Juliette (1867). Verdi's Falstaff (1893) was based on Shakespeare's The Merry Wives of Windsor and scenes from Henry IV, parts 1 and 2. Ambroise Thomas's Hamlet (1868) is rather less well known.
Authors of opera libretti are usually not well known outside the realm of opera. One exception was W. H. Auden, who wrote the libretto for Benjamin Britten's Paul Bunyan (1941) and co-authored the libretto for Stravinsky's The Rake's Progress (1947).
However, have any Western opera libretti ever successfully transitioned from the opera to the theatre stage? By "successfully" I mean that there should have been at least two independent productions of the resulting play (which would be a low bar for an "ordinary" play). I am also using the term "transition" rather loosely here; if any libretto transitioned to the stage, I assume there was some form of adaptation (beyond leaving out the music and singing) rather than simply a staging of the libretto. If yes, what was the first one?
 This excludes musicals.