SHANGHAI — Dustin Johnson tied the course record with 9-under 63, four shots better than anyone else Friday, and built a five-shot lead in the HSBC Champions. It was the kind of score that might make everyone else wonder which course he was playing.
Except Graeme McDowell saw the whole thing.
Crouched behind the 10th green at Sheshan International, McDowell looked over at the powerful American and said, "I've probably seen 18 of the best drives I've seen all year in the last two days."
Moments later, after Johnson blasted another one down the middle, McDowell saw No. 19.
It was an impressive display, Johnson at his best with the most important club in his bag. He ran off six birdies in his opening seven holes. He never hit more than 8-iron into a par 4. He twice came within 15 yards of driving the green on par 4s, once with a 3-iron.
"I really drove the ball really well," Johnson said. "For me, that's a big key."
Johnson became the sixth player with 63 at Sheshan International, last achieved by Martin Kaymer in the final round in 2011. He was at 12-under 132, five shots clear of first-round leader Rory McIlroy (72), Bubba Watson (69) and Boo Weekley (67).
McIlroy, who started the second round of this World Golf Championships event with a two-shot lead, made three birdies on the front nine to stretch his lead to four. At that point, Johnson was just getting warmed up. And it wasn't long before McIlroy started to cool.
McIlroy drove into the same bunker he was in Thursday and made another bogey, and he didn't give himself any birdie chances over the last six holes.
"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," McIlroy said. "I didn't hit a lot of quality shots on the back nine."
At least he's still in the hunt for his first win of the year.
Plenty of players were poised behind Johnson to make a move.
McDowell (69), Ernie Els (69), Sergio Garcia (68), Gonzalo Fernandez-Castano (71), Tommy Fleetwood (70) and Ian Poulter (67) were at 6 under. Phil Mickelson, trying to recover from his quadruple bogey-bogey finish to the opening round, had 68 and was seven shots behind.
"I'm making a lot of birdies," Mickelson said. "But I've had too many mistakes. I'm going to continue to play aggressively out here because I have to make birdies to catch the lead. And hopefully I'll eliminate a few mistakes here or there."
Champions: Fred Couples took the second-round lead in the Charles Schwab Cup Championship, shooting his second straight 6-under 65 for 12-under 130 in the season-ending event at San Francisco. First-round leader Peter Senior bogeyed the 18th for 69 and fell two strokes back. Bart Bryant (66) was third at 8 under. Bernhard Langer (68) was another stroke back. Points leader Kenny Perry (71) was 3 under.