We use the AdS/CFT correspondence to perform a numerical study of a phase transition in strongly-coupled large-Nc N = 4 Super-Yang-Mills theory on a 3-sphere coupled to a finite number Nf of massive N = 2 hypermultiplets in the fundamental representation of the gauge group. The gravity dual system is a number Nf of probe D7-branes embedded in AdS_5 x S^5. We draw the phase diagram for this theory in the plane of hypermultiplet mass versus temperature and identify for temperatures above the Hawking-Page deconfinement temperature a first-order phase transition line across which the chiral condensate jumps discontinuously.