South Africa's Justin Harding made the most of a "jammy" moment to claim a one-shot lead as home players dominated the opening round of the Tshwane Open.
A total of 10 South African players ended the day inside the top 16, with Jaco van Zyl on four under and defending champion George Coetzee part of an 11-strong group on two under which included Scottish trio Jamie McLeary, Andrew McArthur and Scott Henry.
World No.509 Harding, who chipped in on the 18th to complete a back nine of 30, has missed the cut in his last three events and said: "I'm super chuffed. I have been struggling the last couple of events so it's a confidence boost.
"I felt like I hit it quite nicely although I was quite jammy on the last -- I chipped in from a position that otherwise was not very good. So that was a great way to finish the day.
"It's been a while since I've been up there in one of these events so it's a good feeling. I'm just going to see if I can maybe keep it going.
"I feel as though I'm hitting it nice enough, putting it in the fairway with a driver at least, which is good. I missed a couple of irons off the tee, but that happens."
Spangenberg, who is ranked 1,082th in the world and has made just four halfway cuts in 19 previous European Tour appearances, had gone to the turn in 31 and recovered from a double bogey on the 10th with birdies on the 12th, 15th and 17th.
The 32-year-old had to come through qualifying on Tuesday to secure his place in the tournament, a six-under-par 66 at nearby Woodhill Country Club seeing him finish joint first as 120 players battled for the 15 spots available.
"I've been hitting the ball well and the game seems solid so I was confident coming into this week and didn't doubt myself, both in the qualifier and in today's first round," he said.
"I did drop those two shots at 10 and after initially making a bit of a mess of the 11th I eventually chipped in for par to keep the momentum going, but I hit a lot of fairways and was rolling in the putts."
Former Masters champion Charl Schwartzel, who took advantage of Rory McIlroy's final-round collapse to win at Augusta in 2011, bogeyed two of his last five holes to card a one-over-par 71 in his first appearance since finishing ninth in the Nedbank Golf Challenge on Dec. 6.