Zach Johnson was joined by William McGirt at the top of the leaderboard at the end of day two in the John Deere Classic.
After carding a 63 to earn a share of a three-way tie on Thursday, Johnson continued his good form with a round of 67 to move to 12-under-par in Silvis.
McGirt's 66 was enough to see him draw level with Johnson, but it could have been better had the 35-year-old not followed his rival's lead by finishing his round with a bogey.
Steven Bowditch, Brian Harman and Johnson Wagner are all just one shot behind the leaders, while three-time winner Steve Stricker was among a group on nine-under at the end of the day.
Defending champion Jordan Spieth recovered from a difficult opening round in style to shoot a seven-under, which leaves him five strokes off the pace.
