Louis Oosthuizen fired an 8-under 64 on Friday to grab a one-stroke lead after two rounds of the Volvo Golf Champions.
The 2010 Open champion Oosthuizen sits at 12-under 132 through 36 holes. His second-round 64 was matched only by Scott Jamieson, who is tied for second place with first-round leader Thongchai Jaidee (68) at minus-11.
"I hit it really well today," said Oosthuizen. "A lot of shots I hit exactly the way I wanted to and I'm putting beautifully. I'm finding good speed on the greens and I'm seeing good lines and I'm riding a few in."
The next closest group, which is comprised of former Open champion Paul Lawrie (70), Thomas Bjorn (70), Jeev Milkha Singh (70), Julien Quesne (67), Danny Willett (70) and Shane Lowry (69), sits at 5-under -- good for a fourth place tie.
Like Oosthuizen, Ernie Els entered Friday three strokes off the pace, but the defending Claret Jug winner settled for even-par at soggy Durban Country Club and fell into a tie for 10th place with Francesco Molinari (70) and Nicolas Colsaerts (67) at 4-under.
Three-time major winner Padraig Harrington (71), Jamie Donaldson (72) and Rafael Cabrera-Bello (69) are tied for 13th at minus-3.
The second round was delayed for two hours due to overnight rain and when play resumed defending champion Branden Grace bounced back from Thursday's 75 with a 5-under 67. The South African is tied with three others, including two-time U.S. Open champion Retief Goosen (70), at 2-under.
Oosthuizen, seeking his sixth European Tour win, closed his stellar round with back-to-back birdies to grab the lead, but it was Jamieson who made an early impression.
The Scot is looking to build on a strong start to the current campaign, which saw him win the 2013 season-opening Nelson Mandela Championship and tie for third at the Alfred Dunhill Championship a week later.
Jamieson birdied four of his first six holes on Friday to overcome a four- stroke deficit and catch Jaidee at 7-under.
After some jostling at the top, Jaidee went up by two shots when he eagled the par-5 eighth, but Oosthuizen executed a run of three straight birdies to pull even with the former paratrooper at the turn.
Jamieson remained one back before he too reeled off a trio of successive birdies to grab a one-shot lead through 15 holes. He added a birdie on No. 17 to close at 11-under with Oosthuizen and Jaidee still on the course.
Jaidee then reached 11-under with a birdie on No. 16, but Oosthuizen did one better by picking up a birdie on both of his last two holes to grab sole possession of the lead.
"This is one golf course where you can never get too relaxed," continued Oosthuizen. "There's loads of birdies out there but it can easily sting you. I'm gonna play my same game: fairway, greens; just try to give myself birdie opportunities."
NOTES: Jamieson is seeking his second European Tour win and Jaidee is looking for his sixth ... The field includes the first two winners of the 2013 campaign, every winner from the 2012 European Tour International Schedule, past champions of the event, and golfers with 10 or more European Tour victories ... Last year, Grace birdied the first playoff to hole defeat Els and Goosen.