Marc Leishman finished birdie-birdie in a brilliant round of 66 to take a one-shot lead into the final day of the Nedbank Golf Challenge in Sun City.
The Australian recorded his best European Tour finish at The Open Championship in July when he lost out in a play-off to Zach Johnson at St Andrews, but he will be the man to beat on Sunday after rounds of 68-68-66 got him to 14 under.
Henrik Stenson sits a shot back after a closing bogey dropped him into second place with home favourite Jaco Van Zyl then four shots behind the leader.
Stenson, the 2008 champion at Gary Player Country Club, had looked set to take a comfortable lead in his hunt for a tenth European Tour title but two dropped shots in his last three holes saw him leapfrogged at the top of the leaderboard.
"I saw Henrik was getting away a little bit so I had to try to do something to make it interesting for tomorrow," said Leishman. "Hopefully I can have another good round like today and give him a run for his money.
"I'll be very relaxed – there's not too much to stress about. Obviously I really want to win, but it's golf. I generally sleep well so hopefully I'll do that tonight, and I'll try to make some birdies tomorrow. There's a lot of golf to go and anything can happen.
"I've been in this position a few times in big events so it's great to draw on that experience.
I’ve come up short a couple of times but I’ve won tournaments before and I’m looking forward to having a chance tomorrow - Marc Leishman
He added: "It was a good day. I got the speed of the greens a lot better today. I'd been missing a lot of putts low all week from hitting them a bit soft, so I fixed that today and managed to hole some putts, which was the main difference."
A closing birdie for Van Zyl kept hopes of a first South African winner since Trevor Immelman in 2007 very much alive for the home crowd, with Branden Grace and Louis Oosthuizen also in the top ten.
American Robert Streb matched Van Zyl with a 72 to sit at nine under, but with the rest of the chasing pack at least seven shots back of the leader, they will need something special on the final day.
Leishman made a gain on the first with the pin once again gettable, and Van Zyl also took advantage with a tap-in birdie to join Stenson at the top as the Swede needed two putts from distance to make his par.
Stenson's slightly ragged start continued at the next as he played an air shot at the edge of the green but managed to make par while Van Zyl found the heart of the green and two putts gave him a second birdie and the lead.
Streb had left himself some work to do over a bunker with his third but he hit the pin with his pitch and made a birdie to get to ten under.
Leishman joined him with a birdie on the fifth and all three of the final group parred the third and fourth as the top four pulled away from the rest of the field.
It was all change at the top on the fifth as Van Zyl found a bunker and dropped just his second shot of the week while Stenson made a first birdie of the day to move back ahead by one.
Streb dropped a shot at the sixth with Stenson producing an excellent up-and-down from the sand to keep his nose in front.
A hot putter had carried Stenson to a back nine of 31 in the second round and that continued as he made another clutch putt on the seventh to hold par while Van Zyl dropped a shot to extend the lead to two.
The leader then failed to get up-and-down from a bunker on the eighth as the lead went back down to one and Leishman found the trees off the tee ahead on the ninth but saved his par to turn in 34.
Stenson then made a fortunate birdie on the ninth after just staying out of the water with his second and seeing his putt drop right at the last second, with Van Zyl and Streb following him in for gains of their own.
Meanwhile, ahead on the tenth, Leishman played a brilliant second shot to the par five and holed the eagle putt to move to the top of the leaderboard.
But Stenson and Streb both then birdied the tenth and when Leishman dropped a shot on the 11th, the leader had some breathing space at the top.
Streb dropped a shot on the 11th but Leishman took advantage of the par five 14th for the third time this week to close the gap before Stenson got up-and-down from the sand on the same hole for a birdie.
That required a putt of ten feet and on the 15th the 39 year old holed on from 15 to extend his lead to three shots as Van Zyl and Streb both made par, the latter doing brilliantly after putting his tee shot in the trees.
But Leishman made a gain at the 17th to prevent Stenson from pulling away and, when the 2013 Race to Dubai winner three-putted the par three 16th, the gap was down to one.
An excellent approach had brought Leishman's birdie and when he put his second on the last to five feet, he rolled in the birdie putt to come home in 32 and tie the lead.
A wayward tee shot from Stenson then saw him find the sand on the last and after electing to play out rather than attack, he could only make a bogey to drop back to 13 under.
Van Zyl gave the home crowd something to cheer about with a lengthy putt after back-to-back bogeys while Streb made a par to steady the ship after joining his playing partners in dropping a shot at the 16th.
Behind the leading four, Grace fired a 67 to sit at seven under in a share of fifth. The home favourite opened with a bogey but birdies on the fourth, ninth, tenth, 13th, 14th and 17th powered him into the top ten. Austria's Bernd Wiesberger was also at seven under after six birdies and two bogeys in his round.
Oosthuizen made it three South Africans in the top ten after a 68 got him to six under and he was a shot clear of the Thai duo of Kiradech Aphibarnrat and Thongchai Jaidee and Englishman Chris Wood.
Last week's winner Charl Schwartzel signed for a 67 to get to four under alongside defending champion Danny Willett, Victor Dubuisson and Andy Sullivan.
