Paul Lawrie carded a 3-under 69 on Friday to grab a 1-shot lead after two rounds of the Nedbank Golf Challenge.
Lawrie, the 1999 British Open champion, finished 36 holes at 4-under-par 140.
Martin Kaymer also shot 69 on Friday to move into second place at minus-3.
Bill Haas, who shared the first-round lead with Nicolas Colsaerts, stumbled to a 1-over 73 at Gary Player Country Club to slip into a share of third place at 1-under-par 143. He was joined there by Louis Oosthuizen (72), Charl Schwartzel (71) and Francesco Molinari (71).
Defending champion Lee Westwood tripped to a 1-over 73 to end 36 holes at even-par 144. Peter Hanson (73) is one shot back at plus-1.
Carl Pettersson faltered 3-over 75 to slip into ninth place at 3-over 147. Colsaerts struggled to a 6-over 78 to tumble into a share of 10th at plus-4. He stands alongside Garth Mulroy (73).
World No. 4 Justin Rose fell into last place in the 12-player field after a second-round 79. He ended 36 holes at 8-over 151.
MORE TO FOLLOW.