Justin Thomas held onto his lead at the John Deere Classic by a single stroke on a day of low scores that included the resurgence of world No. 2 Jordan Spieth.
Thomas fired a 4-under 67 to reach 12-under, giving him a 1-stroke lead over Johnson Wagner and Tom Gillis.
Wagner fired an 8-under 63, tying Thomas’ first-round effort. Wagner recorded seven birdies in an eight-hole stretch between No. 6 and No. 13. It allowed him to jump from 37th to a tie for second.
Thomas got off to a fast start with three birdies in his first six holes, but was only 1-under on the back nine because of a bogey on No. 13.
Three-time winner Steve Stricker dropped from fifth to tied for 11th with a 2-under 69, while Spieth, who was tied for 101st after the first round, rallied with a 64 to drop to 7-under, five strokes off the lead and tied for 16th.
Spieth roared out of the gate with three birdies and an eagle on his first seven holes. He slowed up with a bogey on No. 8, but then rallied with three birdies over the final five holes to reach 7-under for the day.
He is tied there with Day 1 co-leader Nicholas Thompson, who sunk like a stone with a 1-over 72, struggling with a trio of bogeys.