"I can see why they call the 17th the hardest par four in golf, it is a very intimidating tee shot," he said.
"We played it where we had to push the tee shot even more towards the hotel and you get that under way and think it's the hard part and then you have to try and hit the green that runs on an angle to the fairway.
"I played a couple of shots out of the bunker and they were hard enough even though they said they have made it easier. A couple of years ago it would have been absolute death in there."
Fox hit a three wood 8 iron downwind on his first round then driver 8 iron into a little breeze and a front pin which could be moved 30m towards the back of the green.
You had to be so precise on holes like the 11th where the shallow green at the par 3 made it tough to get up and down or the 4th which was so demanding. Any bad shots courted trouble and avoiding bunkers like the Spectacles or the Principal's Nose was essential.
Fox walked the course then played a round with Lee Westwood and Byeong Hun An who won the BMW Wentworth this year and then after some introductions through Kiwi caddy Steve Williams, played another nine holes with Adam Scott.
"They were just such cool experiences," Fox said. "The course is fantastic. It is a great layout, quite green for a links course and playing nicely but very differently every time I have been out. It's very exposed and there is nothing to stop the wind blowing across here."
Seeing the course for the first time was more remarkable than he expected and staying in St Andrews with his extended family, was a charming experience.
"There was a lot of wow and a couple of other words you can't use when I teed it up on the first. It is so impressive and such an amazing golf course," he said.
His form was a bit scratchy, his good shots were good but the bad shots were bad. His coach Marcus (Wheelhouse) was there and they'd spent time on the range and ironed a few little things out.
Fox begins his opening round after midnight, about half an hour ahead of compatriot Danny Lee and then is the final man in the field to tee off in the second round.
St Andrews suited his eye, it was generous off the tee if you took the right lines. The greens were tricky because of their size and it was going to be hard to get close to pins on some of the holes.
"If I play well it is a golf course that will suit my eye but if you don't get it right it can make you look a little silly as well," Fox said.
