McIlroy carded seven birdies and two bogies at the Glendower Golf Club in his first European Tour event of the year, so honouring a promise to tournament host Ernie Els to play in the second-oldest national open in the world.
The Northern Irishman was one of five players to record an opening 67, along with locals Thomas Aiken, Jbe Kruger and Dean Burmester, and England’s Jordan Smith.
"I didn't realise how far the ball went here,” McIlroy told reporters. “It's a long golf course but when it heats up like this, the ball goes a long way. You really have to think your way around. It's a great golf course.
"I started off with a solid run of pars and then made a nice run of birdies there on the back nine. I gave myself plenty of chances and probably missed a few.
“I played well. It was a bit adventurous on the back nine, I scrambled a good bit and did my bit to try and salvage a few holes.”
McIlroy is behind Fisher Junior, who at one stage had a run of six birdies in seven holes, and another home favourite, Horne. Both carded six-under-par 66s.
“I played well. It was a bit adventurous on the back nine, I scrambled a good bit and did my bit to try and salvage a few holes.”
McIlroy is behind Fisher Junior, who at one stage had a run of six birdies in seven holes, and another home favourite, Horne. Both carded six-under-par 66s.
