TORONTO -- Corey Conners shot a bogey-free 5-under 67 on Thursday to share the first-round lead at the RBC Canadian Open.

Conners is seeking to become the tournament's first Canadian winner in 69 years. Also at 67 were Aaron Rai, Justin Lower and Chesson Hadley.

Two-time defending champion Rory McIlroy opened with a 71 at Oakdale. Matt Fitzpatrick, who will seek to defend his U.S. Open title next week at Los Angeles Country Club, was one of nine players at 68.

Conners’ two PGA Tour victories both came at the Valero Texas Open, including this year.

“Really disciplined off the tee, we didn’t try to do too much,” said Danny Sahl, Conners' caddie. “But he had tons of fairways, missed maybe a couple in the first cut.

“Corey’s just tee-to-green hitting greens in regulation, made some good putts, just strong all around.”

Mike Weir in 2008 was the first Canadian to lead after the first round. The 53-year-old Weir shot 72 Thursday in his 30th Canadian Open appearance.

Canadians Mackenzie Hughes, Taylor Pendrith and Roger Sloan were among the group at 3-under par.

“You can’t win it on Thursday, but you can lose it,” Hughes said. “So definitely nice to be in a good spot after Thursday but it’s going to take four quite nice rounds and some steady golf.”

An air quality advisory was in effect due to wildfires across Ontario and Quebec that have led to postponements of sporting events in the northeastern United States. There was some rain during the afternoon, but play was never delayed.