Justin Harding fired an opening 63 to set the clubhouse target on day one of the Tshwane Open at Pretoria Country Club.
The South African is searching for his first European Tour top ten in his 33rd event and has some serious pedigree in his homeland with four wins on The Sunshine Tour.
He showed that quality on Thursday, registering eight birdies against a single dropped shot to get to seven under, two shots clear of countryman Theunis Spangenberg.
Spangenberg is also a winner on The Sunshine Tour, having claimed the 2011 Africom Zimbabwe Open, and could be pleased with his morning's work having missed his last 11 cuts on The European Tour, dating back to 2013.
Jaco Van Zyl, last season's Turkish Airlines Open runner-up, was then at four under, a shot clear of another South African in Merrick Bremner.
Harding turned in 33 with a bogey and three birdies on the front nine but really came to life after the turn with a run of three birdies from the 11th. It looked like he would share the lead with Spangenberg, who had been in the third group out, but a birdie-birdie finish then gave him the lead on his own.
Spangenberg flew out of the blocks to turn in 31 but then double bogeyed the tenth before picking a shot back up at the 12th, with further birdies following on the 15th and 17th.
Van Zyl has nine top threes on The European Tour but has yet to enter the winner's circle, although he was only denied by a brilliant finish from Victor Dubuisson at The Montgomerie Maxx Royal in November.
After starting on the tenth, he turned in 34 with two bogeys and three birdies on the back nine before birdies on the third, sixth and ninth moved him into contention.
Bremner had six birdies and three bogeys in his 67, with defending champion George Coetzee then in the group at two under, alongside fellow South Africans Shaun Norris and Ulrich van den Berg, Scottish trio Andrew McArthur, Jamie McLeary and Scott Henry, and Englishman Robert Dinwiddie.
Joburg Open champion Haydn Porteous fired a level par 70 to sit a shot clear of fellow 2016 winners Charl Schwartzel and Brandon Stone.