My belief is that it is not a question of priority at all. It is impossible to interpret scripture without the light of some theological system, and contradictions in that system need to be resolved.
But systematic theology, concerns of linguistics, local concerns about what we know of the author's intent, background, and rhetorical style -- all of that play the role of consistency checks. They can disqualify or refine poor readings, even as the scriptures themselves are an important source of theology, knowledge of the author and culture/linguistics. So the question is not what creates what, but whether the combination of all these is consistent.
The source of interpretation has to be revelation, but it is very easy to fool yourself into thinking that something is a revelation when it is not, and for that you need to throw everything at the revelation to see if it can withstand it, and systematic theology would be one of those things thrown, along with everything else.