Indeed. I won't argue whether Lepanto or Vienna was the more important victory over the Turkish expansion, but they were both absolutely crucial.
Also, perhaps, Ivan the Terrible's conquests of the Mongols. Ivan was not, to say the least, an admirable or saintly man, but he accomplished one crucial job, at least.
Correcto, Cicero.
From now on we'll call him, Ivan "the mostly" Terrible