Tony Finau saw his overnight lead cut to two shots as the final round of the WGC-HSBC Champions got under way at Sheshan International Golf Club.
The American teed off with a three-shot lead for the second day in a row and played his first four holes in level par to stay at 13 under and in top spot.
But defending champion and playing partner Justin Rose picked a shot up to get to 11 under, a shot clear American Xander Schauffele and two ahead of Tommy Fleetwood and Patrick Reed.
Finau and Schauffele are both looking for maiden wins on the European Tour while victories for the other leading contenders could have even bigger consequences.
Fleetwood and Reed would move to the top of the Race to Dubai Rankings presented by Rolex with a victory, while a win for Rose would see him move back to the top of the Official World Golf Ranking.
Fleetwood holed an 18-footer on the first to get to nine under and when Finau missed from inside five feet on the same hole, that was just three back.
Finau recovered beautifully, getting on the green at the par five second in two to make a birdie, but Schauffele and Rose both played excellent bunker shots for birdies of their own.
Fleetwood could not take advantage of the par five but he had his eye in on the greens in the early stages, holing a long putt on the third to get back within three of the lead.
Rose needed to hole an eight-footer on the third as the final trio all made par but ahead on the par three fourth, Fleetwood three-putted and Reed found sand off the tee for their first bogeys of the day.
The leading trio were all in bunkers off the fourth tee but Schauffele was the only one to fail to get up and down and he fell back to ten under.
Andrew Putnam was at eight under, a shot clear of Kiradech Aphibarnrat and Jason Day.