1
general::
Phrase(s): give the devil his due [and] give the devil her due
Fig. to give your foe proper credit (for something). (This usually refers to a person who has been evil—like the devil.) • She’s very messy in the kitchen, but I have to give the devil her due. She bakes a terrific cherry pie. • John is a bit too nosy, but he keeps his yard clean and is a kind neighbor. I’ll give the devil his due.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Give credit to what is good in a disagreeable or disliked person. For example, I don't like John's views on education, but give the devil his due, he always has something important to say, or I don't like what the new management has done, but give the devil his due, sales have improved. [Late 1500s]
American Heritage Idioms