Louis Oosthuizen refused to look too far ahead after opening a five-shot lead at the halfway stage of the WGC-HSBC Champions in Shenzhen.
The South African followed his opening 65 with a course-record 63 in the second round to put clear daylight between himself and his nearest challenger Adam Scott.
"I'm in a great position to win, but it's not even crossed my mind at the moment," said Oosthuizen, who won the 2010 Open by seven shots.
"There's still a lot of golf to be played - I need to put myself in a great position going down the back nine on Sunday."
Oosthuizen had three birdies and an eagle on the four par-fives on the Mission Hills course and was pleased with the way he putted during his nine-under effort.
"I started off a bit shaky with a bogey on the second, but immediately made birdie and was putting really well," he said.
"I gave myself a lot of opportunities for birdie and if you make the putts you shoot a low number."
Ernie Els made light of an ankle injury to match Oosthuizen's 63 and sit in a tie for second place at 11-under alongside Australian Adam Scott.
In his first event back since the ankle problem, Els was thinking of that magical 59 at one stage, but was happy enough with his overall effort.
"I wish I can always play like that," said Els. "That number (59) was crossing my mind. You know, I just didn't quite make the putts coming in."
"I feel it, but it's all right. You know, what do say, be aware of the injured golfer.
Scott stuttered slightly in his back nine after an outward 32, but he is still well in contention in second after his round.
"I missed a few greens out there and misjudged the chips, tricky chips, but still, you know, I'm pretty happy with 68. It wasn't my best stuff out there, but moving in the right direction," said Scott.
"Five shots is a lot when you've got a guy like Louis out in front. He's a player who can get hot and shoot a low score like he did today. If he does that over the weekend, he's going to make it really difficult for anyone to catch him."
Ireland's Shane Lowry is the highest placed of the European contingent in a tie for fourth at 10 under, six behind Oosthuizen.
Of his second-round 68, Lowry said: "I didn't birdie two easy par fives and made a bad bogey on the sixth, but other than that I played lovely all day and gave myself a lot of chances.
"What's not to enjoy? I'm playing a World Golf Championship and I'm up there in the top five going into the weekend."