The 28-year-old from Knoxville, Tennessee, who matched his first round score of 66 on Friday, recorded six birdies - five of them coming on the back nine - as he leads from a group of four a further shot back.
Kevin Chappell carded 68 on Friday to add to his opening 65 at the Sea Island course and sits alongside fellow American's Briny Baird, Webb Simson, and Australia's John Senden on seven under par.
Despite a windswept day Simpson made three birdies and just one bogey and following his second round he said on pgatour.com: "Before I played I would take anything under par.
"I think the game plan before the round (was to know) club selection so you don't get to a hole and you're shocked and you don't know what to do. That was big for us."
Early leader George McNeill suffered a poor second round and sits in tie for 27th.
Thursday's first round was interrupted by heavy fog causing play to be suspended due to bad light, and McNeill, who claimed a one-shot lead as he completed his delayed first round earlier on Friday, slipped up as he could only manage 76 - 14 more shots than his first round - to leave him two under par.
The 38-year-old from Florida started off well, but ended up with seven bogeys - five of them on consecutive holes on the back nine before he claimed a birdie on the 15th - which moved him down the leaderboard and he was joined by compatriots Martin Flores, Harris English, Heath Slocum, Zach Johnson, Australian Stuart Appleby and Zimbabwe's Brendon de Jonge on two under.
Jason Kokrak was in a strong position after his second-round included an eagle and four birdies for a 65 score.
Kokrak, who on Tuesday scored a hole-in-one on the 409 yard par-four 5th hole at the Pro-Am, finished six under par at the halfway stage.
Meanwhile Matt Kuchar and Will Claxton were just two shots back after they completed their second rounds on Friday.
Vijay Singh missed the cut as he followed up his first-round 69 with 73 with five bogeys it total taking him two over par overall.