Elsewhere in Europe, Ryan Fox is five shots off the lead after the first round of the Celtic Classic in Wales.
Fox carded two birdies in a bogey-free round to sit in a tie for 34th at two-under par. Fellow Kiwi Michael Campbell rallied with two birdies in his final three holes to shoot even-par.
Belgium's Thomas Pieters leads at seven-under.
Meanwhile, Danny Lee will be participating in the FedEx Cup playoffs, but Tim Wilkinson is set to miss out.
Wilkinson, who needs to jump into the top 125 in the FedEx Cup standings to make the PGA Tour's playoff series, shot a four-over par 74 in the first round of the Wyndham Championship, the PGA Tour's final regular-season event before the playoffs, to all but end his hopes of making up enough ground to leap from the 148th place in which he came into the tournament.
Lee, who carded a first-round one-under 69, sits comfortably in 53rd on the standings and will be playing next week regardless of whether he makes the cut at the North Carolina tournament.
Harold Varner III, Tom Hoge and Roger Sloan each shot eight-under 62 to share the first-round lead.
The strong start was especially crucial for the 33-year-old Canadian Sloan, who came into the tour's last regular-season event at 178 in FedEx Cup points — well out of the 125 cut off to make next week's first postseason event, the Northern Trust in Boston. Sloan is projected to rise into the top 50 should he maintain his position.
"Honestly, I don't have to do anything," he said. "I'm very blessed that I have status on the PGA Tour next season. That's important. I'm going to get starts, I think that frees you up."
All three leaders are seeking their first tour wins. The trio were two shots in front of Harris English (64). A large group was at five-under led by former Masters champion Patrick Reed. Past U.S. Open champion Webb Simpson led another pack at four-under 66. Paul Casey, who tied for second last week at the PGA Championship, was at 67.
Some other PGA Championship contenders last week were not as fortunate.
Both Brooks Koepka and Justin Rose, each in the mix in the final round of the year's first major, could not keep that going in this one. Koepka was 10 shots behind after a 72. Rose finished a stroke worse.
Koepka said he was flat after playing several weeks in a row.
"A bit tired, to be honest with you, so definitely came out flat," he said. "But I've got to play, I've got no other option."
Koepka said even moving up a spot or two in FedEx Cup standings is helpful to advance, so that's why he passed up a week off to compete.
He also apologised for his comments after the third round at the PGA Championship that he didn't know "a lot of the other guys" on the leaderboard. "I get it, I get how it came across and I apologise for that," Koepka said.
- With AP