Scott Jamieson fired a course-record 63 on Friday to hold a commanding three-shot lead at the halfway stage of the Alfred Dunhill Championship.
Afternoon starter Jamieson produced two impressive birdie bursts during the second round at Leopard Creek Country Club, reeling off four straight gains on the front side before making a hat-trick on the back nine.
The Scot made nine birdies in all and kept his card clean to head into the weekend on 13 under par.
Englishmen Eddie Pepperell and Nathan Kimsey and French DP World Tour Qualifying School graduate David Ravetto were in a three-way tie for second on ten under.
South Africans MJ Daffue, Dean Burmester, Oliver Bekker and Dylan Mostert were another shot further back along with Canada's Aaron Cockerill.
Jamieson opened his birdie account at the par-five second before storming into contention with four birdies in a row at the fifth, sixth, seventh and eighth.
After sending his tee-shot at the short 12th to around ten feet, he knocked in the birdie putt there to get within one of the lead.
Jamieson then birdied the 13th and 14th to make it three in a row, before getting up and down from a bunker at the short 16th for a sensational par save which kept him two clear of the chasing pack.
A ninth birdie of the day at the 17th sent Jamieson three clear as the rain poured down, and he safely parred the last for a spotless 63.
Jamieson said: "It's a special place to hold a course record. Hopefully it holds over the weekend.
"Going bogey-free is always a nice feeling. I holed some crucial par putts at times, which helped to keep the momentum on my side.
"The putter got hot for a couple of stretches on the front nine and on the back nine.
"It was a great day.
"I always love playing golf here. It's my favourite week of the year.
"So yeah, I'm up for the challenge."
