Dustin Johnson remains the man to catch at the WGC-HSBC Champions in China after an amazing third round 66 featuring 10 birdies and two double bogeys.
Despite racking up a six at the par four 10th, Johnson looked all set to maintain or likely increase his overnight five-shot lead when he stood on the 18th tee after clocking up 10 birdies on day three at the par 72 Sheshan International GC.
But that five-shot advantage was reduced to three over defending champion Ian Poulter when the American pushed his tee-shot into water and carded a seven.
After earlier rounds of 69 and 63 that left the seven-time PGA Tour winner on 18-under.
Johnson raced to the turn in just 30 after birdies at three, five, six, seven, eight and nine but, amazingly, found his lead cut to just a shot on the back nine.
That was after he had double bogeyed the 10th after two duffed chips came back to his feet and Poulter - playing three groups behind - had matched Johnson's outward 30 and followed that with another birdie at 10 and an eagle from 15 feet at the par five 14th.
Poulter, who is looking to become only the second player after world number one Tiger Woods to defend a WGC title, parred 15 and 16 and, after a first bogey of the day at 17, he two-putted for birdie at the last to post 15-under.
With Johnson reeling off four straight birdies from the 13th, that left Poulter five back again but Johnson's closing double bogey renewed the Englishman's hopes of defending the title he won at Mission Hills 12 months ago.
Graeme McDowell moved into third place on 14-under - four back - after a bogey-free 64 which included an eagle two at the 16th while first-round leader Rory McIlroy, US Open champion Justin Rose and Canada's Graham DeLaet now share fifth place on 12-under.
Rose finished with four birdies in the last five holes to match DeLaet's 65 while McIlroy, after a slowish start, came home in 32 to finish the day six behind leader Johnson.
The low round of the day came from Ryder Cup hero Martin Kaymer.
After a disappointing Friday 74 the German bettered it by 12 shots on Saturday, his 62 which featured 10 birdies from the second to the 16th setting a new course record.