A horror opening round has an out-of-sorts Cameron Smith in danger of missing the Australian PGA Championship cut in his title defence.

The three-time champion admitted he was in a place no golfer wants to be during a two-over first round of 73 on an otherwise low-scoring day at Brisbane's Royal Queensland.

A lone birdie on the 12th hole, his third of the day, was cancelled out by three bogeys to put him 10 shots behind clubhouse leader Joel Moscatel Nachshon of Spain.

The 2022 British Open champion spent most of Thursday shaking his head as his usually reliable iron game let him down.

"It was frustrating, upsetting; I really couldn't get anything going," Smith said.

"It was just crappy.

"There's no reason why you shouldn't have gone low, it was just pretty terrible golf.

"It was hard to commit to a shot; I felt like I was over the ball not knowing what I was going to do, which is a pretty bad place to be on a golf course."

Smith was pipped for victory at the recent Hong Kong Open and has otherwise produced sterling golf in a 2023 season that yielded two LIV Golf wins and two top-10 major finishes.

Good judges expect the winner on Sunday to finish around 20-under, leaving Smith a mountain to climb - that's if he can bounce back on Friday to avoid a tournament organiser's nightmare and make the cut.

Smith insists he can make up the ground though, confident in his ability on a course that is less forgiving than it sometimes appears.

"I don't think anything's out the window yet; it's going to take a lot of good golf but there's no reason I can't have a good weekend and still be competitive," he said.

"I love this place."