Toronto - Scott Piercy made four-straight birdies on the front nine then held off fellow Americans William McGirt and Robert Garrigus to win the PGA Tour's $5.2 million Canadian Open on Sunday.
Piercy closed with a three-under 67 to finish at 17-under 263 as he tied the oldest 72-hole scoring record on the PGA Tour.
Piercy two-putted from 50 feet for par on the 18th hole of the Hamilton Golf and Country club course to post his second career USPGA Tour victory.
McGirt was atop the leaderboard for much of the fourth round. But he three-putted for bogey on the 15th and failed to save par from a bunker on the final hole for a 69 that left him one shot adrift of Piercy.
Garrigus, the 54-hole leader, fired a 70 after he three-putted the 16th hole for bogey and finished in a tie for second.
Josh Teater and Bud Cauley both shot four-under 66 to seize a share of fourth place. They ended in a tie with Chris Kirk (68) at 14-under-par 266.
Piercy's 263 total matched tournament's scoring record, first set by Johnny Palmer in 1952.
His first victory came in 2011 at the Reno-Tahoe Open, which is next week.
Piercy, of Las Vegas, won't be there to defend as his win Sunday gets him into the WGC-Bridgestone Invitational which takes place at the same time.
"I am so excited. Reno was definitely a platform for me to showcase how good I could really be. If that's any sign as to how this year's been, I think there's a lot of big stuff for me," Piercy said.
Garrigus parred the first 13 holes, gained some momentum with a birdie on 14 but then came the bogey on 16.
He had a opportunity to force a playoff, but couldn't get his 14-footer for birdie at 18 to fall.
"I don't think I was thinking about what I was thinking about the last three days with the putter. My chest was moving too," Garrigus said. "This was my 18th or 19th tournament with the [long putter]. The more and more I play, the more and more comfortable I'll get with the thing."
McGirt's approach on 18 landed in the bunker and he failed to convert an 18-foot par-saving putt.
"It was a struggle to get the butterflies to fly in formation," McGirt said. "I have never been in this situation before and to have a chance to win a golf tournament and have a chance to get into a playoff was something new for me.
"My No. 1 goal coming into this week was to make sure I locked up getting into the (PGA) playoffs.
"My second goal was to make sure I locked up my card and I accomplished both of those today. I would have loved to win the golf tournament, but I played very well all week."
Leading final-round scores on Sunday in the PGA Tour's $5.2 million Canadian Open (USA unless noted, par-70):
263 - Scott Piercy 62-67-67-67
264 - Robert Garrigus 64-66-64-70, William McGirt 63-66-66-69
266 - Bud Cauley 70-63-67-66, Chris Kirk 69-66-63-68, Josh Teater 67-65-68-66
268 - Vijay Singh (FIJ) 65-67-69-67, Scott Stallings 69-66-63-70, Bo Van Pelt 65-66-67-70
270 - Gary Christian (ENG) 71-68-65-66, Retief Goosen (RSA) 68-70-63-69, Nathan Green (AUS) 70-67-65-68, Kevin Kisner 69-65-67-69, Troy Matteson 65-68-69-68
271 - Tim Clark (RSA) 70-62-72-67, Brian Davis (ENG) 69-68-65-69, J.B. Holmes 68-68-64-71, Seung-yul Noh (KOR) 72-66-68-65
272 - Will Claxton 70-66-68-68, Gavin Coles (AUS) 65-69-70-68, Ken Duke 70-65-67-70, Martin Flores 69-67-68-68, Tom Gillis 70-65-73-64, Brian Harman 74-63-71-64, Ryan Palmer 69-67-64-72, Brendon Todd 69-66-66-71, Cameron Tringale 67-69-67-69