WGC-HSBC Champions: Last-hole let-down for Johnson
Despite also making a double-bogey on the 10th, Johnson stood on the 18th tee with his five-shot halfway lead intact thanks to a front nine of 30 for the second day running and four more birdies in succession from the 13th.
However, the big-hitting American then drove into the water down the right-hand side of the par-five 18th and found a greenside bunker with his fourth shot, eventually signing for a seven and third-round 66 to lie 18 under par.
Defending champion Ian Poulter, right, is Johnson’s nearest challenger after a superb 63, with Ryder Cup team-mate Graeme McDowell a shot further back following his 64 at Sheshan International Golf Club.
US Open champion Justin Rose, first-round leader Rory McIlroy and Canada’s Graham DeLaet are all six off the pace on 12 under, Rose and DeLaet having shot 65 and McIlroy a 67. Germany’s Martin Kaymer is 10 under after setting a new course record with a flawless 62.
The only Scot in the field, Stephen Gallacher, slipped eight places to a tie for 63rd despite a 72, one shot better than his two previous efforts.
After his round, Johnson said: “I’m still a little mad from my double-bogey on 18. Obviously to have a three-shot lead going into the last day is good and I am looking forward to the challenge. I still have to play really well.
“The guys that are right behind me, they are playing very well, too. So it’s still going to be a tough day tomorrow. I’ve got to come out and make a lot of birdies.
“If you told me teeing off I would shoot six under I would have taken it, but I obviously left a few shots out there. I’m definitely happy with what I shot. Obviously I’m just not happy with the way I finished.
“Making two doubles, there’s no excuse for that. Especially the way I’m playing right now, it shouldn’t happen. But 66 is still a good day and I did make ten birdies, so I hit a lot of great shots.”
Poulter, looking to become only the second player after world No.1 Tiger Woods to defend a WGC title, had charged up the leaderboard with five birdies in a row from the third and another on the ninth to be out in 30.
The Ryder Cup star also birdied the 10th. When Johnson hit a double-bogey six on that hole, and Poulter then holed from 20ft for an eagle on the 14th, the gap was suddenly down to one. But Johnson responded once more with birdies on the 13th, 14th, 15th and 16th.
Poulter three-putted the 17th for his only bogey of the day but birdied the last to remain firmly in the hunt for the first prize of just over ¤1 million (£856,000).
“Nine under par on any golf course is a good score and that was a good nine under par,” Poulter said. “The only blemish for me, which leaves a sour taste, was three-putting 17, and missing a couple of opportunities.”