Second-round leader Tim Clark stands alone in second at 6-under-par.
Tied for third at 5-under is Chad Campbell. If he can win on Sunday, Campbell would earn the 'battlefield promotion,' which allows any player who wins three Buy.Com Tour events in one year to immediately move up to the PGA Tour.
Todd Fischer, Deane Pappas and Charley Hoffman joined Campbell at 211.
Carter mixed two birdies and a bogey over his first three holes but made his ascent to the top of the leaderboard at the turn.
He wedged his approach at No. 9 to a foot to set up the tap-in birdie and made it back-to-back with a birdie at No. 10. After running home a six-foot birdie at the 11th, Carter drained a 25-footer at the 12th to give him four birdies in a row and the lead at 8-under par.
Carter dropped a shot at the par-3 17th for his 68 but he still held sole possession of first.
The Buy.Com Tour rookie opened with a 74 on Thursday but the tournament took a different shape for Carter in Friday's second round. He holed a 6-iron from 185 yards out for a double-eagle at the par-5 10th.
'The double-eagle yesterday got me going in the right direction,' said Carter, who has three top-10 finishes in the last two months. 'It seems like things are going my way. When something good happens you get more confidence.'
Clark was 2-under on the front nine but he bogeyed the par-4 15th. He got to within one of Carter at the last when he drained a 12-foot birdie putt.
Clark, who notched his third consecutive round of 2-under 70, has barely played this season after injuring his wrist in February.
'I'm still a little weak,' he said. 'I've practiced a lot the last month. I'm still wary of taking a big cut in the rough.'
Jamie Rogers carded a 2-under 70 and is alone in seventh at three-under par.
John Elliott fired a 3-under 69 on Saturday and is the only other player under par in the tournament at minus-one.
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