Shane Lowry carded an impressive 64 to lie three shots off the lead after the opening round of the RBC Canadian Open, but it was a somewhat stuttering start from Rory McIlroy who is seeking a third win in the event.
Lowry, the 2019 runner-up, posted seven birdies, with his only dropped shot of the day coming on 13. He is in a tie for fifth alongside Rasmus Højgaard and the American pair Ricky Castillo and Trey Mullinax on six under.
Leading the way on nine under are Dane Thorbjørn Olesen and Cristobal Del Solar.
Chile's Del Solar, a PGA Tour rookie, bogeyed the par-four 17th before settling for par on the 18th to finish his round and narrowly miss a sub-60 score.
Oleson capped off his day with an eagle on the 18th hole, adding to eight birdies and a bogey.
The pair finished the day one stroke off Carl Pettersson’s 2010 tournament record.
Two-time champion McIlroy was far from his best when posting a one-over 71.
Starting on the back nine at TPC Toronto, he began with a couple of pars but made bogey on 12. Another dropped shot came on 17 as he failed to hole a 20-foot put for par, this after finding the rough.
His response was to make birdies at the next three holes, which included rolling in an 11-foot putt at the second. McIlroy then followed a run of five pars with bogeys on the closing two holes.
Seamus Power withdrew from the event after nine holes.
