Jamie Donaldson strengthened his grip on the Nedbank Golf Challenge with another fine 67 in Sun City.
The 38 year old Welshman held a two shot lead at the halfway stage, but birdied the fourth and fifth this morning to stretch his advantage to four strokes.
The two-time European Tour winner, fifth on the 2013 Race to Dubai, then did well to save par at the long ninth after his approach went in the water, and a birdie at the par five next took him to 14 under par for the week.
He nudged further ahead thereafter as gains came on 11, 14 and 15 and, despite a bogey on the penultimate hole, will head into the final round on 16 under, three strokes ahead of his nearest challengers.
His efforts meant even a fine 66 from Thomas Björn, who came to life just after the turn, was not enough for the Dane to significantly close the gap.
Having managed three birdies on the front nine, Björn began his voyage in with an eagle at ten and birdie at 11, his gains owing much to stunning approaches.
"This is one of the best fields in the world and a three shot lead doesn't mean much," said Donaldson, who won in Abu Dhabi in January and went on to finish fifth in the Race to Dubai in 2013.
"I'm looking forward to the final round. It's going to be a tough day on a difficult course.
"It was hard work out there, even when you are playing well. You can't sit back for a minute, because every hole is difficult. It's very important to stay in the present and keep hitting good shots.
"I'm looking forward to tomorrow. I'll play as aggressively as I can and take on all the shots that I would if it was the first day. I have to go out there and play aggressive golf where I can.
"It would be very special to win. It's a great golf course and a great country. I've won twice on the European Tour so far, but every win is special. This would just be a little more special."
A six at 14 was undoubtedly frustrating yet the veteran picked up a shot on the last to stay alongside America’s Ryan Moore.
Moore, a recent winner on the US PGA Tour, turned in a three under par 33 before picking up two further shots on the back to complete a 67.
Further back on 11 under were Thongchai Jaidee, Sergio Garcia and Henrik Stenson.
Race To Dubai winner Stenson, who hit a solid 69, will wonder what might have been having twice found the water en route to a double bogey at nine.
Garcia, though, will have very differing emotions having produced one of the shots of the day to chip in at 14, his eagle followed by birdies at 16 and 17.
There was no such drama for Jaidee, who did not drop a shot en route to a wonderful 66.