Justin Bolli, who won the Chattanooga Classic in May, posted a 7-under 65. He shares second place with Shane Bertsch (67) at 12-under-par 204. Steven Alker and Anthony Painter overnight co-leader are one stroke further back at minus-11.
Walker came out firing. He two-putted for birdie at the first and came back with a 10-foot birdie putt at the third. The 25-year-old made it two straight with a 12-footer for birdie at the fourth at Fox Den Country Club.
The Panama Championship and Chitimacha Louisiana Open winner kept rolling with a 15-foot birdie at the fifth and capped a run of four straight birdies at the sixth when he dropped a 6-iron within 10 feet of the cup.
Walker moved to 12 under with a 25-foot birdie putt at the eighth. He faltered to a bogey at the next. Around the turn, he erased the error with a 5-foot birdie at the 11th, before chipping in for birdie at the 14th. Walker knocked a sand-wedge to 6 feet to setup birdie at the last.
'I got off to a real quick start,' said Walker. 'I was disappointed with my finish yesterday, but was excited coming into today. I just go out and play each hole at a time.'
If Walker gains win No. 3 on Sunday, he would earn the 'battlefield promotion' to the PGA Tour. That promotion has been accomplished five times in the last five years, and was last done by Tom Carter last season.
'I'm going to have to go out and play a good round of golf tomorrow,' Walker said. 'I won't be thinking about winning, just hitting good shots. I've got a couple of breaks this year.'
Bolli ran off five birdies over his first 10 holes before stumbling to a bogey at the 11th. He came right back to birdie the 12th and notched two more birdies on his way to the clubhouse.
'Just played as well as I could,' said Bolli. 'I'm hitting my irons close to the hole and making some putts. It will probably take 18 or 19 under to win.'
Bertsch scattered one bogey and two birdies over his opening nine. He picked up four birdies on the back nine to grab a share of second place.
Vance Veazey, the other overnight co-leader, managed just an even-par 72 Saturday. He shares sixth place with Hunter Haas and Kyle Thompson at 10- under-par 206. Paul Gow, Darron Stiles and Tim Wilkinson are one stroke further back at minus-9.