Shanghai, China (SportsNetwork.com) - Dustin Johnson fired a course-record tying 9-under 63 on Friday to move five strokes clear of the field after two rounds of the WGC - HSBC Champions.
Johnson, who won the 2013 Hyundai Tournament of Champions, finished 36 holes at 12-under-par 132.
His 63 matched the course record that Daisuke Maruyama, Rory McIlroy and Ernie Els set in 2009. Louis Oosthuizen and Martin Kaymer matched the mark in 2011.
McIlroy, the first-round leader, bogeyed three of his last eight holes en route to an even-par 72. He was joined in second place at minus-7 by Bubba Watson (69) and Boo Weekley (67).
Defending champion Ian Poulter carded a 5-under 67 to move to 6-under-par 138. He shares fifth place with Sergio Garcia (68), Els (69), Graeme McDowell (69), Gonzalo Fernandez-Castano (71) and Tommy Fleetwood (70).
British Open champ Phil Mickelson (68) and U.S. Open winner Justin Rose (71) are among seven players tied for 11th at minus-5 at Sheshan International Golf Club.
McIlroy teed off eight groups ahead of Johnson and looked as though he was going to run away from the field. McIlroy parred his first five holes, then drained three straight birdie chances from the sixth to move to 10-under par, where he was three clear of the field.
Johnson was hot right from the start of his round. He notched birdies at one and two to move to minus-5. After a par on the third, Johnson converted a birdie effort on the par-3 fourth.
The seven-time winner on the PGA Tour birdied each of the next three holes giving him six birdies in the first seven holes. That spurt gave him a share of the lead as McIlroy stumbled to a bogey on the par-4 11th.
McIlroy faltered to another bogey at the 15th to fall one back at minus-8. Johnson tripped to a bogey at the 10th to join McIlroy at 8-under and they shared a 1-stroke lead.
At the par-5 18th, McIlroy drove into a hazard and tried to play out. He later reached the green with his fourth shot, but 2-putted for a closing bogey.
"Obviously, I played nicely on the front nine and then started to hit a lot of sloppy shots on the back. I missed the last six greens in a row, so a bit of work needed on the range this afternoon," admitted McIlroy. "I just hit a couple of bad shots and then I guess I let it affect me a little bit and then I started to doubt myself sometimes. I didn't hit a lot of quality shots on the back nine."
It was all Johnson from there. He rolled in a 15-footer for birdie at the 13th. At the par-5 14th, Johnson chipped his third to a foot and kicked in his birdie effort to move to 10-under.
Johnson chipped to four feet at No. 16 and knocked that birdie in. He closed his round in style as he drained a 12-foot birdie putt at the 18th to finish five clear of the field.
"It started on the range. I started swinging good and hit some good shots. After yesterday, I didn't start off so good. I doubled the third hole of the day, then played really well after that," Johnson said. "This morning on the range I worked on a few things I felt went wrong yesterday, and just started hitting it real good right out of the gate. And, obviously, I putted really well too."
Watson opened with four pars in a row before trading a birdie for a bogey from the fifth. He made the turn at minus-5 after he birdied the ninth.
However, Watson stumbled to a double-bogey on the 10th to fall back to minus-3. He flew back up the leaderboard thanks to four birdies in a 5-hole span from the 13th. Watson parred the last to share second.
Weekley had a streaky round. He started with six consecutive pars from the 10th. Beginning at the 16th, Weekley poured in five birdies in the next six holes to jump to minus-7. He closed his round the same way he started, with six straight pars.
NOTES: Hideki Matsuyama withdrew prior to the second round due to a back injury ... 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 time.