Justin Thomas and Nicholas Thompson carded matching 8-under 63s in Thursday's first round and they share a 1-shot lead at the John Deere Classic.
Thomas is seeking his first career victory on the PGA Tour in his rookie season, while Thompson has also never won on tour.
Luke Guthrie bogeyed the last hole at TPC Deere Run and he fell into a share of third place with Charles Howell III. They shot 7-under 64s.
Three-time champion Steve Stricker is in the hunt once again following his 6- under 65. He is tied for fifth with Robert Garrigus, Daniel Summerhays, Shawn Stefani and Steven Alker.
Defending champion Brian Harman fired a 4-under 67, putting him in a tie for 21st.
Masters and U.S. Open champion Jordan Spieth, who picked up his first career win on tour here in 2013, struggled to an even-par 71 and he is tied for 101st.