Rory McIlroy dropped 16 shots off the pace at the WGC-HSBC Champions in Shanghai after an error-ridden five-over 77 in Friday’s second round.
The 29-year-old reached the turn in 35 after three birdies and two bogeys.
But he bogeyed his 10th, the first, triple bogeyed the next after twice finding water and double-bogeyed 16.
Tony Finau’s 67 left the American three ahead of English duo Tommy Fleetwood (68) and Justin Rose (67) plus overnight leader Patrick Reed (72).
McIlroy’s problems at his 11th, the second, came after he had hit a perfect drive that left him only a short iron into the par five.
However, the world number five’s second shot flew over the green into a water hazard and after he mis-hit his chip, his ball trickled into the same hazard again.
The former world number one is in a share of 58th in the 77-man event heading into the final two days of the no-cut tournament.
McIlroy has not won since claiming the Arnold Palmer Invitational – which was his first victory since 2016 – in the United States in March.
He shared second at the Open Championship in July and claimed top-10 finishes at the final two play-off events in the US before helping Europe regain the Ryder Cup in France.
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