  In this letter we put AdS/CFT dualities involving probe branes to a precision
test. On the holographic side we use a new class of supersymmetric D7-brane
embeddings into AdS$_5\times$S$^5$, which allow to describe N=4 SYM coupled to
massive N=2 supersymmetric flavors on S$^4$. With these embeddings we can
compare holographic results to a field theory analysis of the free energy using
supersymmetric localization. Localization allows us to get results at strong
coupling, and hence to compare in detail to AdS/CFT. We find analytically
matching results: a phase transition at the same critical mass in both
calculations and matching free energies up to a scheme-dependent constant in
both phases.
