They included the pre-tournament favourite, Ernie Els, who won last week's Alfred Dunhill PGA Championship in Johannesburg but could only manage a level-par 71 yesterday. "It was pretty hot out there," said Els. "It's a tough course in the afternoon. The greens are really firm and there was a bit of a breeze, which makes it difficult to keep the ball on the fairway."
Lying joint second on three under were Germany's Alexander Cejka and the South African James Kingston, the only local player to come to terms with the conditions. The Welshman Mark Mouland and Ireland's Paul McGinley were among the players a shot further back on 69 while the former world No 1, Nick Faldo, opened with a one-under 70.
Another Englishman, Anthony Wall, scored a hole in one at the par-three 13th but he had to settle for a two-over-par 73.
The three leaders had all teed off by 7.20am and were back in the clubhouse before the heat of the day had reached its peak of around 35C. A high of 38C is forecast for today.
Garbutt grabbed five birdies and carded just one dropped shot when three- putting from the fringe at the sixth, while Struver, a former South African PGA champion, and McCann bagged four birdies each.
Garbutt, a former English amateur champion, recorded his best round on the European Tour and acknowledged the early tee-off time had been to his advantage.
"To go out at 6.50am was a perfect start. I definitely had the best of the weather because it was cool with hardly any wind," said Garbutt, whose previous best finish was seventh in last year's Dutch Open. "I hit some good iron shots and my putting was much better than in the PGA last week when I finished 38th."
Faldo, who notched up two birdies and an eagle but also carded three bogeys, was another player who teed off early.
"There is no wind and conditions are just perfect for scoring," he said after his round. "The greens are holding, it's there for the taking. Par should be 68, absolute max. Ernie should shoot 65 or 66, and others, too."
However, as the heat increased and the wind picked up, Els struggled after teeing off just before midday despite the overwhelming support of a vocal crowd. The South African began with four straight pars before birdieing the fifth and sixth and looked set for a repeat of his performance last week when he won by a comfortable four shots. But he came adrift at the eighth where, after recovering from a bunker, he missed a short putt to log a bogey five.
On the back nine Els bogeyed holes 10 and 11 before steadying himself and he managed to pull back the two dropped shots by birdieing the 12th and 14th holes only to bogey the 18th to finish the day level.