Alexander Björk turned in 32 to open up a one-shot lead on day three of the Tshwane Open at Pretoria Country Club.
The Swede was playing in just his ninth European Tour event but showed the composure of a veteran to make three birdies on the front nine and move ahead of fellow overnight leader Scott Jamieson.
The Scot made two birdies of his own to sit at 12 under, two shots clear of clubhouse leaders Oliver Fisher and Ben Eccles, and Dean Burmester and Mikko Korhonen.
Fisher was the man to make the first big move, equalling the lowest round of the week with a 62 before the leaders had even teed off.
The Englishman made birdies on the second, fifth, sixth, seventh, tenth, 12th 16th, 17th and had a putt on the last to equal Jacques Blaauw's course record - although preferred lies were in play
His eagle effort from the fringe brushed the hole but he tapped in for another gain to move 48 places up the leaderboard and join Björk and Jamieson in top spot.
That did not last for long, however, as when the leaders did get under way, Björk put his approach to seven feet and opened with a birdie to move a shot ahead.
The 26 year old was clearly zoned-in and got within ten feet on the next to make another birdie and the lead was quickly up to two shots.
Jamieson then holed a ten-footer of his own on the third to cut the gap back to one and a run of pars followed before Björk rolled in a 15-foot effort on the seventh to re-establish his cushion.
A Jamieson birdie on the par five ninth then left the tournament finely poised heading into the back nine.
Australian Eccles had followed an opening 66 with a disappointing 73 on Friday but he bounced back in brilliant fashion with birdies on the second, third, seventh, ninth, 13th, 14th and 17th.
Home favourite Burmester started with a bogey but then made four birdies in a row and added another after a smart up-and-down on the ninth to sit three off the lead after 11 holes.
Korhonen also got up and down from sand on the ninth to add to birdies on the second and third.
Zander Lombard and Peter Uihlein both signed for rounds of 65 to sit at nine under alongside Thomas Aiken, James Morrison and Peter Karmis, all of whom had just made the turn.
Trevor Immelman had earlier made the seventh hole-in-one of the season at the par three fifth. The 2008 Masters Tournament champion holed a seven iron from 201 yards with what was just his fifth shot on that hole all week.
