Zach Johnson and William McGirt were at 12-under-par 130 and tied for the lead at the halfway point of the John Deere Classic.
They were a stroke ahead of Steven Bowditch, Johnson Wagner and Brian Harman.
Three-time Deere winner Steve Stricker shot a 65 Friday for a 133 total to vault into contention at the par-71 TPC Deere Run, and was tied for sixth with Rory Sabbatini, Ryan Moore and Todd Hamilton.
Johnson, the Deere winner in 2012, shot a 4-under 67 in the afternoon despite two bogeys in his last four holes.
That dropped him into a tie with McGirt.
McGirt, 35, is looking for his first PGA Tour victory.