Three birdies in his final four holes last night giveMcIlroy a one-shot lead heading into the last day of action.
McIlroy shot a second consecutive 67 to head the field on thirteen under par, to remain on course for back-to-back Major titles.
He's nearest challenger is Austria's Bernd Wiesberger who hauled himself into contention with a flawless 65.
Graeme McDowell begins the final round from one over par, while Shane Lowry will be in the first pairing and starts the day from three over par.
McIlroy is happy to start the final round top of the leaderboard despite not playing at his best.