"I love playing here - it's a great course, apart from it being very hot," said Benson.
"I was aggressive in the right areas. When I had the chance to go for it I did.
"It's so hot that sometimes you have to take a few deep breaths. Everyone out there is affected."
Kruger eagled the 541 yard 18th and grabbed seven birdies. He would have led on his own but for a bogey at the short 16th.
“Starting my round so well was a blessing because it takes so much pressure off the rest of your round,” he said.
They are two ahead of Scots George Murray and Alan McLean, France's Jean-Baptiste Gonnet and South African George Coetzee, who can close in on the Sunshine Tour Order of Merit with victory in the co-sanctioned event.
Murray, joint third in the Alfred Dunhill Links Championship at St Andrews last month, racked up ten birdies, but also had two bogeys and a double bogey on the tenth.
Former Ryder Cuppers Oliver Wilson and Phillip Price, 132nd and 118th respectively on The Race to Dubai, both managed only a two over 74.
The top 115 retain their cards following the UBS Hong Kong Open in a fortnight.
Kruger, 25, has no such worries after securing his card for 2012 with a 13th place finish in the Barclays Singapore Open on Sunday.
But having never won away from the Sunshine Tour, he is keen to add European Tour winner to his CV.
“The frustration at not yet winning is there to build my character,” he added. “Sure, winning is always in my mind because you want to prove yourself worthy. But it’s about taking it one shot at a time, and the rest will take care of itself.”