SILVIS, Illinois, July 13, 2012 (AFP) - Matteson's 13-under par total of 129 gave him a one-stroke lead over Jeff Maggert and Brian Harman.
Maggert climbed up the leaderboard with a bogey-free round of nine-under 62, matching his career-low round. He capped his effort with a 13-foot birdie putt at the ninth.
Harman notched his second straight 65 to join Maggert on 130.
"I saw the putts better today," Maggert said. "But I'm going to be aggressive tomorrow. I feel I need another really low round Saturday or Sunday, seven- or eight-under, to be in contention."
J.J. Henry (64), England's Gary Christian (66), Robert Garrigus (66) and Ricky Barnes (67) were tied on 131.
A trio of players on 10-under 132 included three-time defending champion Steve Stricker, who stayed within striking distance with a four-under 67.
"I like the spot I'm in," Stricker said. "I'd rather kind of be there at this point.
"I'm hitting better putts," Stricker said. "I feel my confidence coming back. I'm standing over putts thinking I've got a good opportunity to make them, even from 20 to 30 feet."
Matteson, a two-time winner on the US PGA Tour, launched his round with an 11-foot birdie putt at the first.
He two-putted for birdie on the par-five second.
He parred the next seven holes but picked up two more birdies at 10 and 14 before his lone miscue of the day at the par-four 15th.
"Greens were a lot smoother this morning," Matteson said. "They weren't a lot faster, but they were a little faster so we couldn't be as aggressive with some of the putts.
"The wind picked up for a few holes, so I know that changed the way a few guys played holes. I know holes like No. 5 played 40 yards longer."
Leading second-round scores on Friday in the $4.6 million John Deere Classic US PGA Tour event (USA unless noted):
129 - Troy Matteson 61-68
130 - Jeff Maggert 68-62, Brian Harman 65-65
131 - J.J. Henry 67-64, Gary Christian (ENG) 65-66, Ricky Barnes 64-67, Robert Garrigus 65-66
132 - Steve Stricker 65-67, Tommy Biershenk 66-66, Lee Janzen 67-65
133 - Ben Crane 66-67, Y.E. Yang (KOR) 68-65, John Senden (AUS) 69-64, Luke Guthrie 65-68, Ted Potter 67-66, Zach Johnson 68-65, Chris DiMarco 66-67
134 - Martin Flores 67-67, Chris Couch 67-67, Scott Piercy 65-69, John Merrick 67-67, Bobby Gates 66-68
135 - Duffy Waldorf 66-69, Alex Cejka (GER) 67-68, Dicky Pride 67-68, Tim Clark (RSA) 67-68, Tommy Gainey 69-66, Rory Sabbatini (RSA) 67-68, Stuart Appleby (AUS) 66-69, Tom Gillis 66-69