Patrick Damron, Franklin Langham, Keoke Cotner, Eduardo Herrera and Chip Sullivan were two shots off the pace at 8-under-par 64.
While several players posted low scores early on, Green saved the best for late in the day with an afternoon tee time and rocketed out of the gate with birdies on each of his first three holes.
The 29-year-old then birdied the par-4 fifth and moved to 5 under on his round with a birdie at the par-4 10th.
Green, who has only made the cut in one of three tournaments on the Nationwide Tour this season, picked up another birdie at the par-4 13th before catching fire over the closing holes.
The Australian ran off back-to-back birdies starting at the 15th and made it three in a row with a birdie at the 17th.
Green then took advantage of the par-five last and birdied 18 to make it four straight.
'It's been a long while since I played well,' said Green, who almost had to Monday Qualify for the event. 'I've just been trying to be patient with it but I haven't had a great deal of success in the last year and a half.'
Damron tallied five birdies over his first nine holes and birdied the 10th to keep the run going.
The 25-year-old former Demon Deacon hit his second to 9 feet for a birdie at the par-4 15th and added a birdie at the last for his share of second.
Langham, who captured this year's Rheem Classic, tallied eight birdies and no bogeys for his 64.
Daniel Chopra, Gavin Coles, Hunter Haas, Will Mackenzie, Mike Sullivan, Jeff Street, Scott Sterling and Darron Stiles shared seventh place at 7-under-par 65.
Nationwide Tour money leader Jimmy Walker was one shot further back in a group at 6-under-par 66.