Updated

Shanghai, China (SportsNetwork.com) - Dustin Johnson recorded two double bogeys on Saturday, but still managed a 6-under 66 to maintain the lead of the WGC - HSBC Champions.

Johnson finished 54 holes at Sheshan International Golf Club at 18-under-par 198. He will seek his eighth career PGA Tour win and second this year on Sunday.

"I played really well again today. If you would have told me I'd shoot 6- under, I would have taken it," said Johnson. "Obviously there's good scores out there, so I just have to come out tomorrow and do the same thing. Just drive it into the fairway, hit some greens and roll in the putts."

Defending champion Ian Poulter fired a 9-under 63 to jump into second place at 15-under 201, while Graeme McDowell shot a 64 to sit in third at 14-under.

Rory McIlroy (67), Justin Rose (65) and Graham DeLaet (65) are tied for fourth at minus-12.

Martin Kaymer fired a course-record 10-under 62 to vault into a share of seventh place with Bubba Watson (69) and Boo Weekley (69) at 10-under 206.

Johnson opened his round with a pair of pars before rolling in a birdie at the third to move to 13-under.

Poulter, meanwhile, was making a run up the leaderboard with five straight birdies from the third to pull within two strokes of the lead at 11-under.

But he would get no closer for the moment, as Johnson battled back with three consecutive gains from the fifth, capped by a 5-foot putt at the eighth, to pull ahead by five at minus-16.

Poulter then followed a lengthy birdie putt at the ninth with another gain at the 10th to pull back within three at 13-under, but Johnson continued his torrid pace by making it five birdies in a row at the eighth and ninth to regain his 5-stroke lead at 18-under.

Johnson ran into some trouble at the par-4 10th after his second shot rolled off the front of the green and down a steep incline into the damp grass. He would need three attempts to escape en route to a double bogey, dropping him to 16-under.

Moments later, Poulter found the green in two at the par-5 14th and converted his 15-foot eagle effort to cut his deficit to just one at minus-15.

Johnson, however, quickly regained his cushion with a birdie at the 13th that he followed with a 2-putt birdie at the 14th. He kept rolling with another gain at the 15th to build his lead back up to four strokes at 19-under.

That advantage increased to five when Poulter 3-putted for bogey at the 17th to fall to 14-under and into a tie for second with McDowell, who chipped in from a greenside bunker for an eagle at the 16th meet him there.

McDowell, who also recorded six birdies during his bogey-free round, parred his final two holes.

Johnson then converted his fourth straight birdie at the 16th to pull further ahead at 20-under.

Poulter bounced back from his lone bogey of the day with a 2-putt birdie at the last to finish at 15-under.

"Any time you shoot 9-under on any golf course then that is obviously a great round," Poulter said. "To 3-putt on 17 obviously left a bit of a sour taste in my mouth and there were -- it seems silly to say -- a lot of other chances too, but I've done what I set out to and got myself in the mix. It'll be great to go head to head with Dustin tomorrow and hopefully I can get a lot of birdies and a couple of eagles and finish lower than him."

Johnson was later forced to take a second tee shot at the 18th after his first found the water. His next shot settled in a greenside bunker and he blasted out for a double-bogey 7, dropping his lead to three heading into the final round.

Kaymer's impressive round included 10 birdies, including three sets of three straight, and no bogeys.

"I had a few unexpected birdies which always helps," said Kaymer. "Before this round I would have said top ten was the most realistic aim I had, but obviously I'm going to be pushing now to finish as high as possible."

NOTES: Johnson has converted one of his previous three career 54-hole leads into a victory. He was also the 54-hole leader at three events (2013 Hyundai Tournament of Champions, 2011 Barclays, 2009 AT&T Pebble Beach National Pro- Am) that were reduced to three rounds due to weather ... Poulter is looking to join Tiger Woods as the only two players to successfully defend a World Golf Championship title, something Woods has done eight times.