Last week's winner Christiaan Bezuidenhout was one of four home favourites in the six strong group at the top of the leaderboard after the first round of the 2020 South African Open.
Fresh from his magnificent four shot victory at last week's Alfred Dunhill Championship, home favourite Bezuidenhout - starting at the tenth on Thursday morning - made five birdies on his front nine before mixing one birdie with the only bogey of his round on the homeward nine to sign for an opening 67.
Morning starters Schwab, Bezuidenhout, Kruyswijk and Burmester made the most of favourable early scoring conditions at Gary Player Country Club, while Korb and Zemmer had the wind to contend with in the afternoon.
That did not stop them from making big moves, though, with Korb - a winner in South Africa last month - making six birdies in seven holes around the turn to take the outright lead on six under before a bogey on the eighth, his penultimate hole, dropped him into a share of the lead.
He said: "It's been a lovely day for me. I played pretty well. Actually I hit only one poor shot there on the 17th and it cost me just one single drop but I managed to just keep calm."
Zemmer, meanwhile, closed his round with a birdie at the ninth to sign for a 67 which contained six birdies and a single bogey.
"I'm very pleased with my score today," said Zemmer. "In the afternoon we had quite a lot of wind so I'm pretty happy with how I played."
Bezuidenhout has enjoyed enormous success on home soil so far this year, winning the Dimension Data Pro-Am - co-sanctioned by the European Challenge Tour - in February before clinching his second European Tour title at Leopard Creek Country Club four days ago.
And the 26-year-old continued to shine on Thursday morning as he opened his first round with successive birdies at the tenth and 11th before taking advantage of the two par threes on his front nine - the 13th and 16th.
Bezuidenhout, who is up to ninth on the Race to Dubai Rankings Presented by Rolex following last week's win, reached the turn in 31 after picking up another shot at the long 18th.
He began his back nine with another birdie to jump to six under but gave the shot back on the short third.
The World Number 41 gave himself chances to go even lower towards the end of his round but was unable to convert his birdie tries from inside ten feet at the seventh and ninth.
He said: "I got off to a nice start this morning, turned in five under par. I birdied the tenth as well to get to six under par and then just from there the putter all of a sudden went cold. I just couldn't make putts coming in.
"I was hitting it nicely, gave myself quite a few chances so the hitting is there. Hopefully I can keep on rolling it well over the next few days.
"Overall I'm pleased with my start and hopefully I can keep it up over the next few days."
Schwab turned in 33 courtesy of birdies at the 11th, 15th and 18th, before draining his 20 foot eagle putt at the first to get to five under.
Speaking about his eagle, Schwab said: "I came off a nice birdie on my ninth hole of the day and then hit a good drive, hit a good four iron to, I'd say 18 feet and then holed the putt.
"It was a pretty straightforward eagle so that was nice for me."
After carding four birdies and a solitary bogey in his first nine holes Burmester, who also started from the tenth tee, reeled off a hat-trick of gains at the third, fourth and fifth to climb to the head of the leaderboard on six under.
He would remain alone at the top of the pile until a bogey on the ninth - his final hole - saw him drop into the group on five under.
"If you gave it to me before I teed off I would have taken it," said Burmester about his opening 67.
Kruyswijk, meanwhile, made four birdies and two bogeys on the front nine before adding further birdies at the 11th, 14th and 15th.
He said: "It really means a lot. It's been a hard few months for me. After lockdown I suffered a bit of a back injury which put me out for a few months.
"The confidence was very low the last few events. It's just one of those situations where you sort of stick to your process and just push through a little bit and I'm very happy with my round today."
South Africa's Dylan Frittelli and Frenchman Matthieu Pavon were a single shot off the lead in a tie for seventh.