Playing at Millbrook Resort, Murray's morning round was matched late in the day by New Zealander Harry Bateman, who played his last six holes in six under, while Japan's Ryuko Tokimatsu is also at eight-under following a 64 on The Hills course.
Murray began his quest with a birdie on the par-five 10th before adding more birdies at 13, 16 and 17 to turn at four under.
It was more of the same on the front nine for the 21-year-old, who picked up another shot at the par-four 4th before a hat-trick of birdies of holes 6, 7 and 8.
Murray is chasing his second full-field PGA Tour of Australasia win having won last year’s WA Open and was also victorious at the innovative Blitz Golf event in Adelaide in January.
Murray, Bateman and Tokimatsu sit two shots clear of Japan's Kodai Ichihara.
Four players share fifth at five under: Thailand's Panuphol Pittayarat, Ashley Hall, Maverick Antcliff and Japan's Yoshitaka Takeya.
Among the other notables, top-ranked Kiwi Ryan Fox is well placed following a 3 under 68 at Millbrook, K.J. Choi is at 2 under and defending champion Daniel Nisbet is 1 under.
Michael Campbell made his return to professional golf after a lengthy hiatus and opened with an even par 72 at The Hills to share 87th while Victorian Geoff Ogilvy battled to a 1 over 73 on the same course to be tied 110th.
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