Now only England's Luke Donald is ahead of the 22-year-old US Open champion thanks to his fourth place finish at the WGC-HSBC Champions event.
If he had parred the 18th McIlroy would have been in a four-way tie for sixth and would have stayed behind Lee Westwood in the rankings.
But he hit his approach to the par five to the back of the green and two-putted - watched by Westwood, who came only just 13th after a disappointing closing 74.
Martin Kaymer's victory after a magnificent 63 containing nine birdies in the last 12 holes has lifted him back to fourth and giving Europe the top four places again.
Donald missed the tournament while awaiting the birth of his second daughter, but was too far ahead to be caught even if Westwood or McIlroy had won.