Tjaart van der Walt (69), Leonard Loxton (64) and Paddy Gribben (68) share fifth place at 8-under-par.
Play is contested over the Lost City Country Club Course and the Gary Player Country Club over the first two rounds but play will stay at the Player Course over the weekend.
Goosen, who fired a 63 on Thursday at the Lost City Course, needed eagles at his first and last holes to offset a pair of bogeys midway through the round at the Player Course.
'I lacked concentration out there today. I had quite a few birdie chances, but just couldn't make the putts,' said Goosen, the winner of last week's Johnnie Walker Classic.
'I felt a bit drained for some reason. And I was under-reading a lot of the putts. I was struggling to focus. But it was nice to finish with an eagle and tied for the lead. I'll get a good night's sleep and I'm sure I'll feel a lot better tomorrow.'
Drummond posted a 5-under 67 on Friday at the Gary Player Course. He was flawless on the front with four birdies over five holes but his mistake came at the 160-yard 13th, where he dropped his lone shot of the day.
Defending champion Darren Clarke shot a 68 on Friday and stands at 3-under-par 141, along with Nick Price, who carded an even-par 72 in round two.
Lee Westwood missed the cut by a single stroke with a second-round 75. The Englishman came in at two-over 146 while players at 145 and better made it to the weekend.
Full-Field Scores from the Dimension Data Pro-Am