Rory McIlroy carded a third consecutive round of 67 to take a one shot lead into the final day of the WGC-HSBC Champions.
The World Number Two is going in search of a third World Golf Championships title and he was bogey free in moving to 15 under and edging one clear of Louis Oosthuizen.
The South African has a Claret Jug in his trophy collection but has never won a WGC event - losing out in the final of the WGC-Dell Match Play three years ago.
England's Matthew Fitzpatrick and defending champion Xander Schauffele were at 13 under, a shot clear of another Englishman in Paul Waring.
A victory for McIlroy would be his first European Tour triumph since 2016 and see him join just Tiger Woods and Dustin Johnson in having won three of the four WGC events.
"I think if I can go out tomorrow and play similar to how I did today, I should have a good chance to win," he said.
"I probably played the best today that I've played all week. I drove the ball well, hitting my irons pretty good for the most part. I feel like I didn't quite get as much out of the round as I could have but I'm not going to complain.
"I'm in the lead going into tomorrow so I just need to rest up and try to get out there and play another good, solid round of golf.
"I've given myself another opportunity to win a very big golf tournament, a tournament that I've never won before. So I want to go out there and be committed, play aggressively and shoot a good number."
Overnight leader Fitzpatrick put his approach to two feet at the first and while neither he or McIlroy could reach the green in two at the par five second, they both got up and down for birdie.
Oosthuizen quickly moved within one of the lead with a remarkable five birdie start.
A gain from 15 feet on the second was sandwiched by birdies from closer range, before he holed a ten footer on the fourth and put his approach to the fifth to tap-in range.
McIlroy hit an excellent tee shot into the par three sixth and he was within one of the lead, with Oosthuizen dropping back after finding a nasty lie with his third on the par five eighth.
Fitzpatrick then three putted the seventh after finding sand off the tee but a nice bounce off the bank at the eighth left him a short putt for birdie.
The pin was near the water at the treacherous ninth but McIlroy took the brave line and was rewarded with a birdie that moved him to the top of the leaderboard alongside Fitzpatrick at the turn.
Oosthuizen made a right to lefter for birdie at the tenth and when Fitzpatrick went left off the tee and played a poor chip at the 11th, McIlroy led alone.
He was joined by Oosthuizen who got up and down from the back of the par five tenth but both McIlroy and Fitzpatrick also took advantage of the par five.
Oosthuizen joined the lead again from six feet at the 16th but then failed to get up and down from the sand on the par three next before making a two putt birdie on the par five last.
Fitzpatrick missed the green on the 17th but picked the shot back up on the last, with McIlroy laying up and putting his approach to close range to lead the way.
American Schauffele bookended his 68 with hat-tricks of birdies, while Waring - making his WGC debut - also made two sets of three from the first and 15th and chipped in at the ninth in a round of 66.
Sungjae Im and Jason Kokrak were at 11 under, a shot clear of Abraham Ancer and Kevin Kisner, and two ahead of Christiaan Bezuidenhout, Victor Perez and Matthias Schwab.
