Glover shot his second straight 66 to move to 10-under and take a one-stroke lead over defending champion Boo Weekley (64) at Harbour Town Golf Links.
Anthony Kim (67) was alone in third at 8 under, with two-time Verizon Heritage winner Stewart Cink (68), Cliff Kresge (66), and Stephen Ames (64) another shot behind.
Jim Furyk, ranked ninth in the world, had his second 68 to head a large group four shots back at 6 under.
When Glovers game is faltering'as it has much of this year'the 28-year-old pro withdraws into his psyche as he tries to find a solution.
Ive been a pain at home, (that) would be fair, Glover said. But I take it out on myself and kind of clam up in my own little shell.
Glover and his game have opened up the first two days. He weaseled his way into the lead Thursday with two late birdies, then used four birdies on his back nine to push past Weekley into first.
Its been a rough season for Glover, who has surpassed $2 million in earnings in 2005 and 2006, and played for the U.S. team in last years Presidents Cup.
He hadnt finished better than 22nd his first eight events. Glover felt hed uncovered a problem with his ball positioning and posture at the Shell Houston Open, where he posted his first top-15 placing.
Glover missed the Masters for the first time in three years, further fueling his motivation to improve for Harbour Town.
I told myself I had to go to work and its not going to come easy, Glover said. I was able to do it the last couple of days.
Hell have to hold off a horde of just-as-eager challengers on the weekend, most notably Weekley.
Weekley had three birdies, all on putts of 10 feet or more, over a stretch of four holes on his back nine to move up the leaderboard. Perhaps no ones enjoyed his champions year as much as Weekley'he laughed about marching around the lagoon in his plaid champions jacket during this weeks opening ceremonies'and wasnt ready to hand over the tartan coat yet.
Weekley felt he could win again on the first hole on the first day. All I had do was just stay focused and hitting my points and my shots, he said.
He might be right. In just his second appearance here, Weekleys shown a touch usually only gained through experience. All six career rounds at Harbour Town have been in the 60s.
Its always fun to be able to look out on the crowd and see all the people pulling for you and chanting your name, Weekley said. I always have a place in my heart for Harbour Town.
Weekleys crowd may get a run from Glovers gallery. Glover is a South Carolina native who played his college golf at Clemson and says his plays been lifted by the large group of family and friends, including his parents, several cousins, his inlaws and his grandfather. Sorry if he ran over anybodys foot, Glover joked.
Still, Glover wont allow himself to jump ahead to late Sunday and a possible victory. I dont think Ive ever been in this position, he said. So Ill figure it out tonight.
Five-time champion Davis Love III, who was tied with Glover and Justin Leonard after the first round, shot a 71 and was five shots back.
Ernie Els figured to have as good a chance to win as anyone, ranked third in the world and finishing second and finishing second, seventh and third his past three times here.
But Els was out of sorts for the second straight round, shooting a 76 to miss the cut.
Justin Rose, ranked seventh in the world, withdrew from the tournament prior to the start of the second round with a bad back. Mark Calcavecchia also pulled out mid-round because of illness. Robert Allenby and Ben Curtis aced the par-3 fourth hole. Tommy Two Gloves Gainey, a South Carolina golfer who won the Golf Channels Big Break VII, hit three balls into the water on the par-4 10th hole to finish with a 10. There were 75 golfers who made the 1-over par cut. Those joining Els outside the ropes this weekend were 2007 Masters champ Zach Johnson, J.B. Holmes and Sean OHair.