As an alternative to the already mentioned "Genugtuung" I want to suggest
Triumph
Beside these two I do not know of any single word that can express this emotion. But there are some idiomatic phrases that I think are worth mentioning:
ein Sieg wie David über Goliath
has something of "clever beats awful" in it, but doesn't really express pleasure. And maybe you need an educated audience to be understood.
ein innerer Reichsparteitag
can express very deep satisfaction that things went - eventually and against some odds - the way you wanted to. But it is also referring to the Third Reich, which can make using this phrase a problem. I list it here for you to know in case you might hear it. You can find some examples here. The phrase even has its own Wikipedia article. They mention two synonyms there:
innerer Vorbeimarsch
jemandem ein Volksfest sein
that I would consider less problematic, especially the latter (but in turn I can't remember having ever heard it).