A single word meaning "success but not without hard work"?

Solution 1:

Why not simply achievement

a thing done successfully, typically by effort, courage, or skill

Or perhaps accomplishment

something difficult that you succeed in doing, especially after working hard over a period of time

Solution 2:

A 'triumph' implies that the success required effort. Similarly a 'conquest' or 'to conquer [a challenge]' may carry this meaning in a nice package. Likewise the idiom "to make headway" isn't one word but carries a meaning akin to succeeding in spite of significant barriers. To 'overcome [something]' may be what you are looking for if there is a specific barrier.

Solution 3:

As a verb, you could say surmount or overcome. Both imply achieving victory despite difficulties. But I can't think of noun forms of those words.