South Africa's Charl Schwartzel stayed on course for a second Alfred Dunhill Championship, taking the outright lead after Friday's second round.
On another blazingly hot day, Schwartzel carded a 4-under-par 68 for the second straight day to claim a two-stroke lead over Englishman Oliver Wilson.
Schwartzel established an advantage over the rest of the field with seven birdies, including three straight starting at the 13th hole - his fourth - at Leopard Creek. That stretch was offset by three bogeys.
"I started well but finished badly," Schwartzel said. "But I played well. I thought I would be in for a nice, low score once again. I was 6-under through nine and I've been striking the ball very well. I stand over the ball and I know where it's going to go.
"But at the seventh, my caddie and I started disagreeing on yardages and things went a little south from there."
The 2004 winner, Schwartzel felt his indecision about yardages with his caddie led to his struggles at the end of the front nine.
"I felt a 7-iron was more than enough (on the seventh hole), and he felt I should hit an 8-iron," he said. "Same thing happened at the eighth. I really wanted to separate myself from the field ahead of the weekend. But a 68 is no disgrace, and I'm still in the lead. That's good enough."
Wilson, who shared the lead with Schwartzel after the opening round, shot a 2-under 70 to claim a share of second at 138 with Spain's Rafa Cabrera Bello, who shot a 3-under 69.
European Ryder Cup hero Lee Westwood, playing with Schwartzel, fired a 6-under 66 to climb within striking distance at 5-under 139.
England's Phillip Archer and South Africa's Wayne de Haas, both of whom registered a 68 in the opening round, carded matching 72s and headline a group of six players at 4-under 140.
Among the group tied for fifth are Spain's Alvaro Quiros (66) and South Africans Ian Hutchings (70), Hennie Otto (69) and Titch Moore (64), who fired the low round of the day.
Defending champion Ernie Els surged to 3-under though five holes and raised hopes he would stamp his authority on the tournament. But South Africa's three-time major winner ran into trouble with a double-bogey at the par-4 eighth and followed with dropped shots at the 10th, 11th and 12th.
Just when Els looked like he was deteriorating, he conjured some last-gasp magic with a birdie at the 15th and a 25-foot eagle at the 18th.
"I don't know what is going on at the moment," said Els, who shot 72 to remain at even par. "Sometimes the wheels just come off. I can't remember when I was last 3-over after 14 holes.
"At the moment, I am just feeling relief. I knew I had to make birdies to make the cut. Now I am back to even, but I have 36 holes left and with two scores of 64, I can still get in there."
Ireland's David Higgins, who was tied for second after Thursday, retired after nine holes due to dehydration.
136 Charl Schwartzel (Rsa) 68 68
138 Oliver Wilson 68 70, Rafael Bello (Spa) 69 69
139 Lee Westwood 73 66
140 Ian Hutchings (Rsa) 70 70, Titch Moore (Rsa) 76 64, Hennie Otto (Rsa) 71 69, Wayne De Haas (Rsa) 68 72, Phillip Archer 68 72, Alvaro Quiros (Spa) 74 66
142 Mattias Eliasson (Swe) 73 69, Ross Fisher 73 69, Liam Bond 71 71, Benn Barham 70 72, Euan Little 72 70, Jaco Van Zyl (Rsa) 73 69, Darren Fichardt (Rsa) 72 70, Alessandro Tadini (Ita) 68 74, Alan Michell (Rsa) 69 73, Desmond Terblanche (Rsa) 70 72
143 Sam Walker 69 74, Keith Horne (Rsa) 72 71, Tyrone Van Aswegen (Rsa) 73 70, Steve Van Vuuren (Rsa) 69 74, Marc Cayeux (Zim) 74 69, Trevor Fisher Jnr (Rsa) 71 72
144 Jean-Baptiste Gonnet (Fra) 75 69, Patrik Sjoland (Swe) 72 72, Adilson Da Silva (Bra) 72 72, Simon Nash (USA) 69 75, Andre Cruse (Rsa) 71 73, Johan Axgren (Swe) 70 74, Robert Rock 70 74, Grant Muller (Rsa) 71 73, Ernie Els (Rsa) 72 72, Richard Finch 78 66, Tom Whitehouse 71 73, Sam Little 74 70, Vaughn Groenewald (Rsa) 71 73
145 Joakim Backstrom (Swe) 73 72, Juan Parron (Spa) 75 70, Henrik Nystrom (Swe) 75 70, Neil Cheetham 73 72, Jesus Maria Arruti (Spa) 73 72, Andrew Coltart 69 76, Andrew McLardy (Rsa) 70 75, Lee Slattery 72 73, Lee S James 72 73, Werner Geyer (Rsa) 71 74, Mark Murless (Rsa) 74 71, James Kamte (Rsa) 71 74, Edward Rush 73 72
146 Anton Haig (Rsa) 78 68, Jean Hugo (Rsa) 73 73, Pelle Edberg (Swe) 70 76, Rafael Echenique (Arg) 72 74, Fredrik Andersson Hed (Swe) 74 72, Alan McLean 77 69, Michiel Bothma (Rsa) 73 73, David Drysdale 73 73, Ross Wellington (Rsa) 75 71, Sven Struver (Ger) 76 70, Hendrik Buhrmann (Rsa) 71 75, Jonathan Lomas 73 73, Jean-Francois Lucquin (Fra) 76 70
The following players failed to make the cut:
147 David Carter 72 75, Andrew Butterfield 72 75, Shaun Norris (Rsa) 76 71, Bobby Lincoln (Rsa) 73 74, Andrew Raitt 71 76, Mads Vibe-Hastrup (Den) 72 75, Gary Lockerbie 71 76, Carl Suneson (Spa) 73 74, Eirik Tage Johansen (Nor) 72 75, Gregory Bourdy (Fra) 74 73, Lindani Ndwandwe (Rsa) 75 72
148 Andrew Tampion (Aus) 74 74, Ulrich Van Den Berg (Rsa) 72 76, Gerlou Roux (Rsa) 72 76, Julien Foret (Por) 78 70, Chris Swanepoel (Rsa) 79 69, Louis Oosthuizen (Rsa) 70 78
149 Desvonde Botes (Rsa) 77 72, Thomas Aiken (Rsa) 79 70, Kalle Brink (Swe) 75 74, Bradford Vaughan (Rsa) 74 75, Grant Veenstra (Rsa) 77 72, Nick Lawrence (Rsa) 76 73, Daniel Vancsik (Arg) 78 71, Adrien Mork (Fra) 76 73, Edoardo Molinari (Ita) 75 74, Manuel Quiros (Spa) 78 71, Sean Farrell (Zim) 74 75
150 Alex Haindl (Rsa) 76 74, Kevin Stone (Rsa) 73 77, Brett Liddle (Rsa) 76 74, Sion Bebb 76 74, Julien Clement (Swi) 73 77, Richard McEvoy 77 73, Malcolm MacKenzie 73 77, Michael Kirk (USA) 72 78
151 Henk Alberts (Rsa) 75 76, James Kingston (Rsa) 76 75, Francois Delamontagne (Fra) 77 74, Rossouw Loubser (Rsa) 75 76, James Heath 74 77, Chris Williams (Rsa) 74 77, Warren Bennett 75 76, Peter Karmis (Rsa) 74 77, Justin Walters (Rsa) 79 72
152 Birgir Hafthorsson (Is) 77 75, Carlos Rodiles (Spa) 75 77, Jeff Inglis (Rsa) 80 72, Phil Worthington 77 75, Callie Swart (Rsa) 76 76, Warren Abery (Rsa) 76 76, Dion Fourie (Rsa) 75 77, Ryan Tipping (Rsa) 75 77, Martin Maritz (Rsa) 75 77
153 Garry Houston 76 77, Matthew Richardson 79 74, Martin Erlandsson (Swe) 77 76, Luis Claverie (Spa) 83 70, David Frost (Rsa) 77 76, Dean Lambert (Rsa) 81 72, Wallie Coetsee (Rsa) 74 79, Blanche Lamprecht (Rsa) 71 82, Michael Lamb (Zim) 73 80