Ireland's Shane Lowry recovered from a poor start to remain the man to catch in the £5.4million Abu Dhabi HSBC
Lowry added a second round of 70 to his course record-equaling 62 on day one to post a halfway total of 12 under par, a shot ahead of former Open champion Louis Oosthuizen and another South African, Richard Sterne.
Lee Westwood is two shots off the lead after a bogey-free 68, with Ian Poulter, Tom Lewis, Scott Jamieson and Soren Kjeldsen a shot further back on nine under.
Lowry saw his three-shot overnight lead wiped out as he bogeyed the second and third, but the 31-year-old bounced back with birdies at the fifth, seventh, 12th and 15th to remain on course for his first win since the 2015 WGC Bridgestone Invitational.
'I'm really happy with that,' Lowry said. 'I knew today was going to be a bit of a weird day after shooting such a low score yesterday. I just tried to go out and play like I played.
'Some of the shots early on were pretty horrendous, so I battled back and hit some really nice shots out there and hit some in close and made some birdies. I was happy with myself.
'I was in Dubai for 12 days before I came up here and pretty much I was practising, training every day. I was there with Paul Dunne and we had a really nice time, we practised together and had some matches.
'I didn't actually beat him once, so I wasn't coming up here too optimistic, but I knew I had done everything right to get myself in a good frame of mind to play here. To be going out playing with Louis tomorrow, I'll enjoy that and hopefully I can go out and make a good show of myself.'
Oosthuizen has finished no worse than seventh in his last three starts, a run which includes a first victory in his national Open in Johannesburg.
'It meant a lot to me,' Oosthuizen said after a 68 containing six birdies and two bogeys. 'It was one that I really wanted and always had scheduling problems to play it.
'It was always up against a big family holiday we have, and last year was the first time that I could actually play it in the last six, seven years, and I was delighted to win.'
Defending champion Tommy Fleetwood, who is seeking a third straight win in the event, birdied the 18th to make the cut on the mark of three under par.
'It was nice to get one in,' Fleetwood said after his 72. 'My putting was pretty awful today. The things that I wanted to do better from yesterday, I did, but just a couple of short ones were missed and then I just holed nothing at any makeable range.
'But you can't stress enough the importance of just making cuts anyway in professional golf. That's the game. It doesn't matter what level you're at. Making cuts is great and I'm very happy that I've gotten another two days of golf.'