Chad Collins stumbled to a bogey on his final hole to take second place at 8-under-par 64. A pair of players looking for their first Nationwide Tour win, Bubba Watson and Brad Ott, share third place at minus-7.
Coles opened his round on the back nine and quickly picked up an eagle at the par-5 11th. He came right back with a birdie on the 12th. After a pair of pars, the 2004 New Zealand PGA Championship winner, dropped in a birdie at the 15th to move to minus-4.
The 35-year-old Coles ran off five consecutive pars around the turn. He then drained birdie attempts at the third and fifth to climb to 6 under at Highland Springs Country Club.
He converted a birdie putt at the seventh and made it two straight as he birdied the eighth. Coles capped his round with his third straight birdie.
'I don't think I mis-hit a shot all day, but if I did it was the driver on the last hole and that one hit the fairway,' said Coles, who finished eighth here in 2002. 'It felt easy out there because the putts were going in. Today was a lot of fun. We're just here to have fun this week whether it goes in or not.'
Collins also began on the back nine and started with back-to-back birdies from the 10th. He notched his third birdie at the 13th, but tripped to a bogey at the very next hole.
Starting at the 17th, Collins ran off four consecutive birdies around the turn to jump to 6 under. He sank another birdie at the fifth before birdieing the sixth to get to minus-8. After a birdie at the eighth gave him a share of the lead, Collins bogeyed the ninth, his 18th, to slip into second place.
'I just played a solid round today,' said Collins, who Monday qualified last week and finished 10th to earn a spot in this field. 'I kept the ball in the fairway and gave myself a lot of looks. I had a lot of 10- and 12-footers and made my share of them. I'm excited about the rest of the week. I just hope to keep having top-25 finishes the rest of the year.'
Tom Scherrer, the runner-up at the season-opening Panama Open, posted a 6- under-par 66. He shares fifth place with Brad Adamonis, Tyler Williamson and Kevin Haefner.
David McKenzie, Eduardo Herrera and Brent Schwarzrock are one stroke further back at minus-5.
Kevin Stadler, a two-time winner this year, carded a 4-under-par 68. He is tied there by 14 other players including Hunter Haas and Franklin Langham, who have each picked up one win this season.