World number six and pre-tournament favourite Louis Oosthuizen holed big putts at the final two holes to snatch the halfway lead in the Volvo Golf Champions at Durban Country Club.
Oosthuizen's two closing birdies gave him a superb bogey-free 64 for a 36-hole total of 12-under 132 and edged him in front of Scott Jamieson and first round leader Thongchai Jaidee.
Jamieson, who captured the Nelson Mandela Championship at nearby Royal Durban just seven weeks ago, had earlier raced through the field after posting a 64 of his own while Jaidee's solid 68, which included an eagle at the eighth, kept him right in the hunt.
That trio have kicked well clear of the 33-man winners only field with Jamieson and Jaidee six shots in front of the chasing pack.
The six-man group at five-under includes recent Ryder Cup winner Paul Lawrie and Dane Thomas Bjorn who were both round in two-under 70s.
Ernie Els, who has won two South African Opens on this track, endured a disappointing day and having started the day alongside Oosthuizen at four-under is now eight shots behind his younger compatriot.
Els was just three shots back after a birdie at 10, but the Open champion dropped shots at 11 and 12 and parred in for a round of 72.
Padraig Harrington's hopes of a charge were halted by a double bogey seven at the 14th and he's now nine in arrears after a one-under 71.
Friday's action was subject to a two-hour delay following heavy overnight rain.