Ben Martin hit a new course record at TPC Louisiana to lead by two shots at the end of day one in the Zurich Classic.
The American registered a round of 62 in fine style, with a chip-in at the 17th hole for a 10th birdie the highlight of an impressive day for the 26-year-old.
Martin's nearest challenger is Andrew Svoboda, who stayed at the top of the leaderboard on eight-under-par for most of the day after equalling the previous course record earlier in the afternoon.
Ryder Cup winner Peter Hanson and Noh Seung-Yul head into the second round in a tie for third - three shots behind the leader.
Martin is aiming for another career-best finish on the PGA Tour after finishing third in the RBC Heritage on Sunday.