American Kevin Kisner has finished the second round of the World Golf Championships-HSBC Champions at the top of the leaderboard following a six-under-par 66 in Shanghai.
Kisner had an unblemished round of six birdies, which has given him an overall two-shot lead, while first-round leader Branden Grace has dropped to four shots off the pace.
Dustin Johnson had an impressive opening day, but struggled in the second round as he managed five birdies while suffering four bogeys, two of which came on the eighth and ninth holes.
However, the American, who has nine wins on the PGA Tour, is not quite out of contention as he is six shots behind the leader.
McIlroy was five shots off the pace in the first round, but the former world number one is now 10 shots off top spot following a second-round 72.
The Northern Irishman scored four birdies, but dropped a shot on four holes.