Sean Shahi birdied his final hole on Saturday to close out a 6-under 66 and claim a 1-stroke lead at The Great Waterway Classic.
Shahi finished 54 holes at Upper Canada Golf Course at 18-under-par 198.
Hugo Leon carded a 5-under 67 to grab second place at 17-under, while Chris Epperson sits alone in third at minus-15.
Tony Finau (67) and Ryan Blaum (70) share fourth place at 14-under 202.
Shahi opened his third round with a par before rolling in three straight birdies from the second.
He recorded birdies at the ninth and 11th to move to 17-under, and then followed six straight pars with a 15-foot birdie putt at the last to claim the outright lead.
Leon collected birdies at the first, fourth and sixth before tripping to a bogey at the seventh.
He bounced right back with a birdie at the eighth, and then traded another bogey for a birdie at the 12th and 13th to stay at 15-under.
Leon closed his round with consecutive birdies at the 17th and 18th to end at 17-under.
NOTES: The second round had to be completed Saturday morning after play was suspended for the second straight day on Friday ... Shahi is looking to become just the second 54-hole leader to win on PGA Tour Canada this season. Joe Panzeri was the first two weeks ago in Calgary.