Colsaerts, who will have full member status on both the PGA and European tours in 2013, birdied his opening hole en route to a 2-under 70 on Thursday. While the Belgian dropped only a single shot on the day, Haas had a far more adventurous round at the Gary Player Country Club. The lone American in the 12-man field, Haas recorded five birdies against three bogeys, matching Colsaert's 2-under total.
A two-time defending champion at Sun City, Lee Westwood shot a 1-under 71 Thursday and trails the co-leaders by a single shot. He is joined at that number by a pair of former major champions, as Paul Lawrie and Louis Oosthuizen both also broke par in the opening round.
Playing in his home country, Charl Schwartzel headlines the group at even par after one round, two shots off the pace. Alongside the former Masters champion are European Ryder Cup members Francesco Molinari, Peter Hanson and Martin Kaymer, while Swede Carl Pettersson also shot an even-par 72 a day after the announcement of a proposed ban on anchoring putters that will affect his current putting stroke.
After closing with a Sunday 62 last week in Dubai, Justin Rose bogeyed three consecutive holes on the back nine en route to a 1-over 73 Thursday. He was one of only two players over par on the day, as South African Garth Mulroy struggled to a 3-over 75 in his opening round.