This match should have been the final.
And this will indeed be strike first or die. Neither Safarova nor Azarenka have the defensive skills to absorb each other's first strike. Safarova has been a bit erratic this week, Azarenka more consistent, but I still think Safarova. In two tight sets, probably. Azarenka is more likely to choke, so that may also be a factor.