Pampling carded eight birdies with one bogey and stands at 10-under-par 130 for a one-shot lead over Stephen Ames, Charley Hoffman and Stewart Cink at Colonial Country Club.
Tim Herron and Dean Wilson both shot 4-under 66s to move into a tie for fifth place at 8-under-par 132. They were joined by Peter Lonard, who shot a 66.
Fredrik Jacobson fired a bogey-free, 8-under 62 to move from a tie for 67th place overnight into a tie for eighth place at 7 under. Jacobson finished one shot off the course record of 61, carded previously by six different players.
Jim Furyk (67), Arron Oberholser (68), Richard S. Johnson (65) and Henrik Bjornstad (64) are also at minus-7.
Pampling, who claimed his second PGA TOUR title at the Bay Hill Invitational in March, holds a second-round lead for the first time in his career.
In all, there are 19 players within five shots of his lead. Littered among them are five other 2006 winners: Furyk, Ames, Oberholser, Chad Campbell (5 under) and David Toms (6 under).
Also in the mix is defending champion and two-time Colonial winner Kenny Perry, who shot an even-par 70 on Friday and shares 21st place at four-under.
But they are all looking up at the 36-year-old Pampling, whose win in Orlando earlier this year has helped him reach the top 20 on the PGA TOUR money list -- and feel more relaxed on the course.
'You can look back at two tournaments that you have won now and especially with the Bay Hill not that long ago, you still have the good memories from that,' said Pampling, who claimed his first win at the International in 2004.
Pampling started on the back nine Friday and carded three consecutive birdies to begin his round -- also a good way to get relaxed for the round.
'It just allows you to not be so aggressive on some of the holes,' Pampling said of the start. 'You can play a little more safer, and sometimes I played a little bit too safe.'
Pampling made the turn at 7 under after a birdie at the 17th, then pulled within one of clubhouse leaders Ames and Hoffman with a birdie at the par-5 first. A 20-foot birdie putt at the par-4 second moved him into a tie for the lead at minus-9.
Pampling gave a shot back with a bogey at the par-4 third, but took the outright lead with consecutive birdies from the fifth. He knocked his approach shot stiff at the par-4 sixth and rolled in a 3-foot putt to get to 10 under for the lead.
On his last two holes -- the eighth and ninth -- Pampling saved par from bunkers to retain his lead and complete a personal-best score of 63.
'I feel confident if I miss a green I can get it up and down,' claimed Pampling. 'And I say, 'Keep the momentum going.''
Justin Leonard shot a 3-under 67 to reach 1-under-par 139 -- two shots below the plus-1 cut line. Leonard made his 13th consecutive Colonial cut dating back to 1993 as an amateur.
Two-time Colonial winner Ben Crenshaw also made the cut in his record 32nd start at the event. Crenshaw, 54, shot a 67 to reach even-par -- recovering nicely from an opening-round 73.
Among the notables who missed the cut were 2003 PGA Championship winner Shaun Micheel, three-time PGA TOUR champion Chris DiMarco, and Verizon Heritage winner Aaron Baddeley.
Jason Gore withdrew after injuring his right elbow while hitting a drive on his 12th hole, the par-4 third. He let his club go after the shot, and it struck near a TV camera behind the 12th tee box. After hitting an awkward second shot, Gore followed his caddie's advice of 'You're done.'
'I winced so bad on that second shot that I just gave my scorecard up and walked in,' said Gore.
The reigning 84 Lumber Classic winner was tied for seventh place overnight, but had slipped all the way to 43rd after going 3 over in 11 holes to drop to minus-1 overall.