Fox's regular caddie was taken ill before round one at 13th Beach Golf Club so the Kiwi drafted in wife Anneke as a last minute replacement on the Creek Course.
The field will play both the Creek and Beach Courses this week and Fox decided to focus all his practice time on the latter, with play moving to the tougher, more links style Beach over the weekend.
He showed no adverse effects, however, making an eagle and five birdies along with two bogeys to get to five under after 18 holes.
I hit a lot of good shots today. I probably left a couple out there but you're never going to complain too much with five under as a start
"I've played here ever since the inception of this event so I've played both courses a lot," he said. "I actually didn't even bother looking at the Creek Course this week until today so I guess not seeing it this week and going out and shooting five under, I'm pretty happy.
"The golf courses are tricky enough. It was tough to hole some putts. I've been struggling with that anyway.
"I hit a lot of good shots today. I probably left a couple out there but you're never going to complain too much with five under as a start."