Hideki Matusyama will take a three-shot lead over defending champion Russell Knox in to the final round of the WGC-HSBC Champions in Shanghai, where Rory McIlroy slipped down the leaderboard.
Matsuyama carded a blemish-free 68 at Sheshan International, a total matched by Knox, as McIlroy's title challenge faded after three bogeys in a five-hole stretch along the back line.
McIlroy had temporarily gone within four of the lead after three birdies in his first eight holes, but missed a three-foot putt at 11th and lipped-out from close range at the next
Although the world No 3 picked up shots at the 16th and 18th to close a two-under 70, the Northern Irishman is in the group eight strokes back that also includes Henrik Stenson and Shane Lowry.
Holding a three-shot overnight lead, Matsuyama briefly saw his advantage cut to one when Bill Haas birdied three of his opening six holes.
Knox matched Matsuyama's gain at the second and recovered from a blemish at the third to leave a kick-in birdie at the next, before picking up a shot at the eighth to move within two.
Matsuyama birdied the ninth to restore his three-shot cushion at the turn, as Knox posted a gain at the 13th and recovered from finding the water at the 14th to hole a 25-footer to save par.
A fifth birdie of the day from Knox at the 15th narrowed Matsuyama's lead, with Daniel Berger posting four consecutive gains from the 13th to join the Scot on 14 under.
As Berger three-putted the 17th on his way to closing a five-under 67 and Knox completed the closing stretch in regulation, Matsuyama posted a two-putt birdie at the last to move back three ahead.
Haas and Francesco Molinari lie five shots adrift in tied-fourth, with Rickie Fowler and Ross Fisher a further two strokes adrift.
Matt Kuchar fired a hole-in-one at the par-three 17th on his way to a four-under 68, while former world No 1 Adam Scott moved up the leaderboard with a round-of-the-day 64.
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