(CNN) -- Scotland's David Drysdale maintained his low-scoring to lead the rain-hit Joburg Open in South Africa at the halfway stage on Friday.
Drysdale swung sweetly as he followed up with a second round 68 in South Africa.
Drysdale followed up his opening-day 65 by carding a six-under round of 66 at the Royal Johannesburg and Kensington Golf Club to total 13-under 131.
Without a single dropped shot on his card, Drysdale is a shot clear of South African Oliver Bekker and Michael Hoey from Northern Ireland.
Play was held up for two hours during the afternoon as a fierce thunderstorm hit the European/Sunshine Tour event.
Andrew McLardy, another home player, managed to stay among the chasing pack with his three-under 68 moving him to nine under overall, alongside Englishman Danny Willett, who carded a 66, while Richard McEvoy, Tyrone van Aswegen and Rafael Cabrera Bello are on eight-under 134.
Drysdale, 33, carded four of his five birdies on the front nine to build on his birdie-eagle finish of Thursday.
"I'm very pleased, especially after playing well yesterday with a good eagle finish, which was nice, and just kept it going today, so overall very happy," he told the Press Association.
Joint-overnight leaders Steven Jeppesen and Trevor Fisher Jnr fell right away with the former carding a five-over 77 for three under overall -- and the latter completely coming apart with an eight-over round of 79 on his way to missing the cut.
Defending champion Richard Sterne, who is bidding for a third straight European Tour title, bounced back from his opening-day 71 with a fine round of 66 - five under after two rounds.
"I got off to a slow start this morning, but then birdied five and six, which put me in a better frame of mind. I knew I just had to stay patient because there are a lot of birdies out there," he said.
Two-time major winner Retief Goosen shot a 68 to move to four-under-par for the championship, but nine shots off the pace.