McIlroy fired a 7-under 65 on Friday, making his lone bogey of his week on the opening hole but rebounding with a birdie on No. 2. He closed with a 5-under 31 on the back nine to get to 12-under for the tournament.
McIlroy leads the field in strokes gained: tee to green. He also tied his best 36-hole score relative to par at 12-under. He won the previous three events where he reached that mark, according to the 15th Club's Justin Ray.
Fleetwood held the clubhouse lead after carding 67 in Round 2. The Englishman started Friday's round with two birdies and an eagle, quickly building on his 18-hole lead. He played the remaining 15 holes at only 1-under par.
Jim Furyk fired an 8-under 64 to sit in a tie for third at 9-under par. The 2018 American Ryder Cup captain finds himself surrounded by European Ryder Cup team members, chasing McIlroy and Fleetwood and sharing his position with Ryder Cup legend Ian Poulter.
Tiger Woods shot 71 despite making an ugly quadruple-bogey on the island-green 17th. He's at 3-under in a tie 39th.