Sebastian Munoz birdied his last five holes, Nos. 14-18 en route to an 8-under (63), his lowest round of the season (previous: (64) at R-1 of ZOZO Championship.
Chesson Hadley opened with 8-under (63), his lowest score on Tour since 2017.
Coming off top-five finishes in his last two PGA Tour starts, Hank Lebiodaopened with 7-under 64
Eleven players completed their round bogey-free, including Chesson Hadley, Camilo Villegas and Chez Reavie.
Leaderboard After 18 Holes at John Deere Classic
Sebastian Munoz 63 (-8)
Chesson Hadley 63 (-8)
Hank Lebioda 64 (-7)
Chez Reavie 64 (-7)
Camilo Villegas 64 (-7)