Aaron Cockerill followed up Thursday's opening 64 with a 68 on day two of the 2020 Joburg Open to set the early clubhouse target.
It was a tale of two nines for the Canadian, who reached the turn in 31 after picking up four shots on the front nine, before carding a birdie and two bogeys down the stretch to move to ten under par.
Overnight co-leader Wilco Nienaber sat alongside Cockerill at the top of the leaderboard after eight holes of his second round, having followed up a bogey on the second with three consecutive birdies at the third, fourth and fifth.
Fellow first round leader Shaun Norris was another shot further back on nine under with 13 holes still to play.
Englishman Richard Bland and American Julian Suri were in the clubhouse on eight under, while South African Jacques Blaauw was also at that mark after ten holes.
Cockerill began the day a single shot off the lead but soon navigated his way to the summit after following up a gain on the second with a hat-trick of birdies at fourth, fifth and sixth to jump to 11 under.
The 28-year-old dropped his first shot of the week at the tricky tenth but bounced back with a tap-in birdie on the 14th, having narrowly missed his long eagle try.
Cockerill gave himself a good chance to make another birdie at the par three 15th after sending his tee shot to 20 feet, but his putt pulled up short of the hole.
A second bogey came along at the 16th after Cockerill got into bunker trouble, and although he found the sand again on both the 17th and 18th, he was able to save par on both occasions to head into the weekend on ten under.
Cockerill said: "I'm happy with the three under score. The last four holes out here are very tough so playing them one over really isn't too bad. I had a couple of up-and-downs on the last two.
"Happy with the day overall.
"The front nine is a lot more scoreable, you can really get after it early.
"The back nine is a lot tougher. The tenth and 11th were strong holes into the wind today with tough pins and then the 15th to 18th are going to be tough almost no matter what, so I think that's probably reflected in the scores.
"I was four under on the front and over par on the back. So you've just got to take what it gives you, I guess."