Shanghai: Dustin Johnson of the United States fired a record-equalling nine-under-par 63 to establish a five-shot advantage over the chasing pack after the second round of the WGC-HSBC Champions on Friday.

Major winner Bubba Watson and fellow American Boo Weekley shared second place with world number six Rory McIlroy of Northern Ireland after the trio returned with matching seven-under-par 137 totals at the Sheshan International Golf Club.

Asian Tour honorary member and International Ambassador Ernie Els of South Africa is among the six players bunched in tied-fifth on 138.

Starting his round in tied-eighth, four shots back of McIlroy, Johnson got off to a blistering start with six birdies in his first seven holes.

After dropping his only shot of the day at the par-four 10th, the Ryder Cup star picked up four shots in his last six holes before signing for a 132 total.

“I'm definitely happy where I'm at. I’ve played really well the last two days. I've really driven the ball well and for me, that’s a big key,” said Johnson.

“I don't intend to play defensively. I just play my game which is pretty aggressive. That's my game, so tomorrow I'm going to go out and try to do the same thing which I did today,” added Johnson.

Former world number one McIlroy, who started on the par-four first, reached the turn in 10-under after a hat-trick of birdies from the sixth hole.

However, he struggled to create a single birdie opportunity on his way home and had to return those three shots after bogeys on holes 11, 15 and 18.

“Obviously I played nicely the front nine and then started to hit a lot of sloppy shots on the back. I missed seven greens on the back nine, so there’s a bit of work needed on the range,” said McIlroy.

“It would have been nice to play a bit better and start tomorrow with a few more shots in hand but I guess I'm in a decent position going into the weekend, and still have a great chance at winning this tournament,” added McIlroy.

China’s Liang Wen-chong and Korea’s Jin Jeong finished as the highest-placed Asians after carding rounds of 67 and 69 respectively.

“The key to doing well is patience. I managed to do that today and will continue to adopt the same approach during the weekend rounds,” said Liang, who is the first player from mainland China to win the prestigious Asian Tour Order of Merit title in 2007.

Scores after round 2 of the WGC - HSBC Champions being played at the par 72, 7266 Yards Sheshan International Golf Club course (a- denotes amateur):
132 - Dustin JOHNSON (USA) 69-63.
137 - Bubba WATSON (USA) 68-69, Boo WEEKLEY (USA) 70-67, Rory MCILROY (NIR) 65-72.
138 - Tommy FLEETWOOD (ENG) 68-70, Sergio GARCIA (ESP) 70-68, Gonzalo FDEZ-CASTANO (ESP) 67-71, Ernie ELS (RSA) 69-69, Graeme MCDOWELL (NIR) 69-69, Ian POULTER (ENG) 71-67.
139 - Jin JEONG (KOR) 70-69, LIANG Wen-chong (CHN) 72-67, Phil MICKELSON (USA) 71-68, Justin ROSE (ENG) 68-71, Keegan BRADLEY (USA) 71-68, Graham DELAET (CAN) 71-68, Jordan SPIETH (USA) 68-71.
140 - Billy HORSCHEL (USA) 71-69, Louis OOSTHUIZEN (RSA) 70-70, Jason DUFNER (USA) 73-67, Gaganjeet BHULLAR (IND) 69-71, Mark BROWN (NZL) 72-68.
141 - Mikko ILONEN (FIN) 72-69, Luke DONALD (ENG) 70-71, Francesco MOLINARI (ITA) 72-69, Jamie DONALDSON (WAL) 67-74.
142 - Matteo MANASSERO (ITA) 72-70, Chris WOOD (ENG) 71-71, Paul CASEY (ENG) 69-73, Ken DUKE (USA) 70-72.
143 - Kevin STREELMAN (USA) 70-73, Peter HANSON (SWE) 70-73, Gregory BOURDY (FRA) 75-68, Brian GAY (USA) 71-72, LI Hao Tong (CHN) 72-71, Scott HEND (AUS) 69-74, Derek ERNST (USA) 71-72.
144 - David LYNN (ENG) 74-70, Rickie FOWLER (USA) 74-70, Darren FICHARDT (RSA) 70-74, Bill HAAS (USA) 72-72, Martin KAYMER (GER) 70-74, Thongchai JAIDEE (THA) 76-68, Peter UIHLEIN (USA) 71-73, Ryan MOORE (USA) 70-74, Bo VAN PELT (USA) 77-67, Lee WESTWOOD (ENG) 71-73, HUANG WenYi (CHN) 70-74.
145 - Hiroyuki FUJITA (JPN) 75-70, Masahiro KAWAMURA (JPN) 73-72, Jonas BLIXT (SWE) 70-75, Michael HENDRY (NZL) 72-73, Scott PIERCY (USA) 72-73, Jaco VAN ZYL (RSA) 72-73.
146 - D.A. POINTS (USA) 72-74, Stephen GALLACHER (SCO) 73-73, Michael THOMPSON (USA) 74-72, Thomas BJORN (DEN) 74-72, Jimmy WALKER (USA) 73-73.
147 - John MERRICK (USA) 72-75, Richard STERNE (RSA) 74-73, Kiradech APHIBARNRAT (THA) 69-78, David HOWELL (ENG) 72-75, Brandt SNEDEKER (USA) 73-74.
148 - Daniel POPOVIC (AUS) 77-71, Branden GRACE (RSA) 77-71.
149 - WU Ashun (CHN) 74-75, Nick WATNEY (USA) 75-74, BAEK Seuk-hyun (KOR) 81-68.
150 - Henrik STENSON (SWE) 74-76.
151 - Raphael JACQUELIN (FRA) 81-70, Miguel Angel JIMENEZ (ESP) 75-76, HU Mu (CHN) 76-75.
152 - Brett RUMFORD (AUS) 75-77, George COETZEE (RSA) 75-77.
153 - Ryo ISHIKAWA (JPN) 81-72.
160 - HUANG Ming-Jie (CHN) 83-77.