James Kmate, Benoit Teilleria, Neil Cheetham and Raphael Eyraud share third place at 4-under-par 68 at the Leopard Creek Country Club.
McDonald, a sponsor's invite who got help into the field when Nick Price spoke with tournament organizers, opened on the back nine Thursday. He birdied his first hole, then dropped a shot at the 12th. McDonald closed with three birdies in his last five holes to make the turn at 3-under-par 34.
On the second nine McDonald kept his hot play going with back-to-back birdies from the first. He bogeyed 164-yard, par-3 fifth, but once again netted two birdies in a row, this time from the sixth. That birdie at seven pushed him past Els on the leaderboard, something McDonald definitely noticed.
'When I was on the 15th hole I saw Ernie was already 5 under and that is tough with me being young and this being my first major tour event,' said McDonald, who played on the Hooters Tour last season. 'You just have to try and think of him as another guy. I know he's No. 3 in the world and how good he is. It's unbelievable, but you just have to think about your own game and luckily I managed to find a few birdies.'
Els, a three-time champion of this event, also started on the back nine Thursday. He birdied the 10th, then tallied four more birdies on his opening nine, including a four at when it looked like his drive was headed toward water.
'I thought it went into the water but when I went to look I saw it was just left of the stream and I had a shot,' said Els, who has a house on the Leopard Creek Country Club. 'I played it out to the fairway, hit a wedge onto the green and made a birdie. It was a big swing for me because it could have been a six, seven or anything.'
Els, a three-time major winner, failed to make any birdies on the way into the clubhouse. He missed a short birdie putt at the second hole, but made routine pars over the final seven holes to get within one shot of the first place.
'It is a good start for me and it was a great back nine that I played,' said Els. 'I couldn't get a putt going on the front nine but there aren't so many birdie opportunities there like there are on the back nine where there are three par-fives.'
Des Terblanche, Oliver Wilson, Peter Gustafsson, Warren Abery, Sarel Son-Houi and Manuel Quiros shared seventh place after opening with rounds of 3-under-par 69.
Defending champion Marcel Siem struggled in the first round of his title defense. He carded a 4-over-par 76 and is part of a large group tied for 101st place.