Thriston Lawrence opened the PGA Tour’s John Deere Classic with a five-under-par 66 on Thursday to be in a share of 21st after the first round at TPC Deere Run in Silvis, Illinois, where the winning score has been 20-under par or lower 12 of the last 15 years.

That put him four strokes off the lead which was held at nine-under-par 62 by Dough Ghim of the United States. He had a one stroke edge over fellow countrymen Austin Eckroat and Max Homa.

Lawrence started his round on the 10th, and made three birdies without dropping a shot ahead of the turn. He made three birdies in the first four holes after the turn, but dropped a shot in that run.

Ghim holed out for eagle on the par-4 sixth hole and kept bogeys off his card on a day of low scoring. The conditions were so ideal Ghim wasn’t even sure his 62 would hold up as the lead by the end of the day. With a little more wind in the afternoon, the best anyone could do was 65 by four players.

Aldrich Potgieter, the 20-year-old coming off his first PGA Tour win last week in Detroit, was challenging for the lead until he stalled at the end of his round, took bogey on the par-five 17th and had to settle for a 67. It was a score he shared with the other South African to win on the PGA Tour this season, Garrick Higgo.

Dylan Frottelli had a two-under 69, and Christiaan Bezuidenhout a one-over 72.