Aiken, two-time major winner Goosen and Sweden’s Peter Hedblom were the first group off on South Africa’s south coast to start the Tour’s 2012 Race to Dubai.
Goosen, after bogeying his first hole, had nine birdies, including five consecutive from Nos. 11-15.
Defending champion Louis Oosthuizen was tied for 25th after a 4-under 69.
Aiken had an early eagle on the par-5 No. 11, his third hole. He added birdies on Nos. 16, 17 and 18.
“I’d call that a memorable start,” said Aiken, who earned his first European Tour win in 2011. “I haven’t taken a cover off a club for two weeks. So I have to say, this is a great result.”