But the former Bay of Plenty interprovincial captain, who turned professional earlier this year, regained his composure, making birdies at the ninth, 11th, 13th and a chip-in at the 15th, against a dropped shot at the 10th, to finish on one-under 71 and comfortably inside the cut line among the 73 professionals and amateurs chasing a generous 19 final qualifying spots for the $500,000 Open.
Professionals Corey Hale (Australia) and Pieter Zwart (New Zealand) headed the qualifiers on five-under 67 at Russley. Rotorua schoolboy Peter Lee also qualified with an even-par round, bringing Bay of Plenty's representation at Clearwater to a healthy five players, with Lee and Mount Maunganui's Brad Kendall playing as amateurs, joining pros Muir, US-based Josh Geary and Tauranga's Jared Pender.
Pender, who played the NZ Open twice at The Hills as an amateur, got an invitation courtesy of his seventh placing on the PGA's order of merit. Like Muir he's heading to stage one of the Australasian PGA Q-school at Sandhurst in Melbourne from December 14-16 and needs a decent performance to give his game a kick-start.
"The year's been pretty average on the whole," Pender said during a practice round yesterday at Clearwater. "I haven't played that bad, just chucking in a few bad holes here and there. But I've come here in a good frame of mind with some solid work lately."
Pender will tee it up in pro-ams next Wednesday and Friday before heading across the Tasman on December 12.
The long-hitting former amateur international said big wasn't always the best strategy around Clearwater.
"Staying out of the water is pretty crucial because there's a lot of water around here, making three-wood or three-iron off the tees a pretty good play."
Muir will have Omokoroa teaching pro and coach Mikki Strong on his bag, with the pair making a reconnaissance visit to the course yesterday. He will leave next Thursday for Melbourne to give himself a decent look at the Sandhurst layout.
"When you're growing up as a junior at your home course then the NZ Open is one tournament you always want to play, so it'll be special in that regard, but this week is a bonus week in terms of my preparation for Australia."