The Englishman managed to get himself out of the way, however, and also managed to shoot a 9-under 63 to take a two-stroke lead after the second round of the European Tour's season-opening tournament.
With seven birdies on the first 10 holes, the former top-ranked player was one shot off Lee Westwood's course record at the Gary Player Country Club, giving himself a chance of a memorable end to a pretty average and so far winless 2014.
The only time Donald panicked on the course nestled in the wilderness of northern South Africa was when a large baboon came running toward him as he made his way to his ball. Donald was warned by playing partner Shane Lowry, quickly dodged out of the way and the baboon kept going.
''He didn't really pay any attention to me in the end but gave me a bit of a fright when Shane said, 'Watch out!' They are big and strong and you wouldn't want to mess with them, that's for sure,'' Donald said. ''So I got well out of the way. (I) jumped pretty high.''
Donald's round was four strokes better than anyone else and put him at 10-under 134 overall. He leads Ross Fisher (70) by two strokes, with Alexander Levy (70) a further two shots back at 6 under.
''I felt very in control,'' said Donald, who last won in November 2013 and last claimed a title on the European Tour more than two years ago. ''It's been a while since I felt like that.''
Donald found some of the form with his putter that has been missing since he became the first player to top the end-of-season money lists in both the United States and Europe in 2011. He made nine birdies and no bogeys.
South Africa's top tournament stopped midway through the round for a moment's silence on the anniversary of the death of Nelson Mandela, the country's former president and Nobel Peace Prize winner.
Players removed their caps and bowed their heads after a horn sounded across the course for the tribute.
Westwood, a two-time Nedbank Challenge champion, improved on his opening 72 with a 2-under 70, while U.S. Open champion Martin Kaymer, off a busy 2014 schedule, slipped down to a tie for 24th in the 30-man field with a 3-over 75.
There is no cut at the invitational tournament, which has a $1.25 million winner's check and is the first event on the 2015 European Order of Merit schedule.