Wiktionary
vb. (context idiomatic English) To acknowledge the positive qualities of a person who is unpleasant or disliked.
Wikipedia
Give the Devil His Due is a 1985 Czechoslovak fairytale film directed by Hynek Bočan. In the Czech Republic, it is considered to be one of the most famous fairytale films ever produced. The Original title means "No joking around with devils".
Usage examples of "give the devil his due".
And the lady, to give the devil his due, is a very good sort of lady, and loves the cloth, and is always desirous to do strict justice to it.
To give the devil his due, I had to admit he was a bold and handsome man, and a fine horseman.
Yes, give the devil his due, even though all that about prayers and how the poor ought to be glad because they'll get into heaven, it's just eyewash and nothing at all for Daddy here, it's a darned fine sight when they put on a proper Jesus feast with Christmas tree and what have you.
For Oskar must give the devil his due: his Kassler Rippchen with sauerkraut, his pork kidneys in mustard sauce, his Wiener Schnitzel, and, above all, his carp with cream and horse radish, were splendid to look upon and delectable to smell and taste.