David Howell fired a third-round 68 to take a one-shot lead into the final day of the HSBC Champions in Shanghai.
GB & Ire unless stated
-16 D Howell
-15 N O'Hern (Aus), T Woods (US)
-12 T Wiratchant (Thai)
-11 T Bjorn (Den), M Campbell (NZ), N Dougherty
-10 V Singh (Fij)
-8 P Casey
-7 Pa Lawrie, I Poulter
-3 P Harrington, C Montgomerie, L Westwood
The 30-year-old ended the round on 16- under-par, one ahead of world number one Tiger Woods, who he will have to hold off in the final 18 holes.
Woods sealed a third-round 67 with a birdie at the last and is on 15-under with Australian Nick O'Hern.
Paul Casey is now eight behind Howell after a disappointing 73 while Kenneth Ferrie is on seven under.
Denmark's Thomas Bjorn had three birdies in a flawless 69 to end up on 11- under while Fijian Vijay Singh in on 10 under after a 70.
Colin Montgomerie had a 68, in a round including five birdies, but after a poor start is down in 25th with, among others, Padraig Harrington and Lee Westwood.
Despite missing a birdie chance from three feet at the first, Howell managed to get his putting game together and birdied the next.
He finished the front nine with putts of 15, 25 and 35 feet - first for birdie, then for a bogey six after he had hooked his drive into a ditch and finally for a another birdie.
He claimed another shot at the 10th before he sunk a 25-foot birdie putt at the 13th.
"I think 68 was the worst score I could possibly have scored and it's slightly frustrating to have only a one-shot lead," he said.
"Mentally I'm not sure how to feel. I missed a two-footer on the first and four six to seven-footers at the finish, but holed three or four in the middle where you would expect to hole only one out of 100.
"It's all about winning on Sunday. It's a great opportunity for me, taking on the world's best player with a one-shot lead.
"It's going to be an exciting day and I'm looking forward to the challenge."
Woods picked up two shots before moving back to two off the lead after three-putting the ninth.
But he bounced back with birdies at 11 and 12 before firing an eagle at the 14th only to bogey the next after a bad drive.
He did miss a four-foot birdie opportunity at the 17th before claiming a shot at the last.
"Considering this is the biggest event China have had had it would be very special to have my name associated with it," he said.
"Hopefully I can get the job done, but there's a long way to go and it's not exactly easy to make the short ones.
"I've got to know David the last few years and he's a wonderful competitor."
Meanwhile Woods has admitted that the Presidents Cup is more enjoyable to play in than the Ryder Cup.
"There is no doubt I have more fun in the Presidents Cup," he said.
"Probably because we're all good friends and you see more concessions and more sportsmanship - good sportsmanship.
"That's the way it's supposed to be played and how the Ryder Cup used to be played. Now it's starting to get back to that."