Sun City, South Africa Ernie Els shot his second straight 6-under-par 66 Saturday and led Bernhard Langer by three strokes after the third round of the Nedbank Challenge.
Ireland's Padraig Harrington had a 61 and was four strokes off the lead. His round was the best ever at the resort, but it is not a course record because players took preferred lies on the wet grounds.
"I was a bit more relaxed today, and I wasn't holding back at any stage," Harrington said. "I was being very aggressive."
Els birdied the fifth through 10th holes and was at 17-under 199 entering the last round of the $4.06 million tournament, which offers golf's richest first prize $2 million.
"I'm very pleased with the way things are going," the South African said. "I feel that my putter is working really well for me, so I was a bit disappointed to finish with a bogey."
Langer shot a second consecutive 67, leaving the German at 202 in the 12-player field. Canada's Mike Weir (69) and England's Lee Westwood (70) were at 204.
Spain's Sergio Garcia was at 205, followed by Zimbabwe's Nick Price and Scotland's Colin Montgomerie at 209, South Africa's Retief Goosen, the U.S. Open champ, at 210, Denmark's Thomas Bjorn at 211 and Northern Ireland's Darren Clarke at 217 Jim Furyk was disqualified after acknowledging he misplaced a ball, resulting in an incorrect first-round scorecard.