Toronto - Brent Delahoussaye shot an eight-under 62 to equal the Canadian Open record as Americans dominated the leaderboard after the opening round of the $5.1 million event.
The 29-year-old Delahoussaye took advantage of ideal scoring conditions on Thursday breaking the course record at the St. George's Golf and Country Club.
"The key was probably hitting fairways," said the qualifying school graduate Delahoussaye. "I figured the rough was going to be thick after my practice round.
"I was three under after two and thinking, 'Wow. This could be good."'
Canadian golfing legend George Knudson held the previous course record of 64 which he set in 1968.
Delahoussaye, who started on the 10th tee on Thursday, posted his only professional victory four years ago at the Hooters Tour Classic.
He is the first to shoot a 62 at the Canadian Open since Hunter Mahan in 2007. The first ever to do it was Leonard Thompson in 1981 on Toronto's Glen Abbey course.
Vance Veazey and Brock Mackenzie shot 64s, and Mahan, Dean Wilson, Charley Hoffman, Jimmy Walker, Rich Barcelo, Steve Wheatcroft, Spencer Levin, Daniel Chopra of Sweden and Brian Stuard all fired 65s.
This was the 14th career PGA Tour start for Delahoussaye. He birdied his par-three opening hole then rolled in a 14-foot putt on the next one for an eagle.
Delahoussaye hit 13 of 14 fairways in regulation, 14 of 18 greens and had only 24 putts on the greens.
The 45-year-old Veazey had his putter going as well.
"The putter. That was the key ingredient," Veazey said. "This golf course seems to be about putting it in the fairway and on the greens. You have to hit good shots into the greens because they have slope. And I had a lot of good looks with the putter."
Stephen Ames and Jon Mills topped the 18 Canadians at 67. "I'm surprised how many good scores there are," said Ames.
Lefthander Mike Weir, who is battling tendinitis in his right arm, shot a 72. Like Mills and Ames, Weir is hoping to become the first Canadian winner in 56 years.
"It actually felt a lot better today," Weir said. "I don't want to use an excuse like that. I just didn't play well."
Leading first-round scores on Thursday in the $5.1 million Canadian Open at the St. George's Golf and Country Club (USA unless noted, par-70):
62 - Brent Delahoussaye
64 - Vance Veazey, Brock Mackenzie
65 - Dean Wilson, Hunter Mahan, Charley Hoffman, Jimmy Walker, Rich Barcelo, Steve Wheatcroft, Spencer Levin, Daniel Chopra (SWE), Brian Stuard
Notable others:
66 - Matt Jones (AUS), Tim Clark (RSA), Greg Chalmers (AUS)
67 - Retief Goosen (RSA), Trevor Immelman (RSA), Mark Hensby (AUS), Stephen Ames (CAN), Jon Mills
68 - Camilo Villegas (COL), Nathan Green (AUS), Jeev Milkha Singh (IND), Paul Casey (ENG), James Nitties (AUS), Adam Hadwin (CAN)
69 - Brendon de Jonge (ZIM), Luke Donald (ENG), Matt Hill (CAN), Jarrod Lyle (AUS), Danny Lee (NZL), Arjun Atwal (IND), Charlie Wi (KOR), Stuart Appleby (AUS), Ryuji Imada (JPN)
70 - Cameron Percy (AUS), Garth Mulroy (RSA), Steve Elkington (AUS), Graham DeLaet (CAN), Aaron Baddeley (AUS), Carlos Franco (PAR)
71 - Mathias Gronberg (SWE), Carl Pettersson (SWE), Brenden Pappas (RSA), Nick Taylor (CAN), Andrew McLardy (RSA), Eugene Wong (CAN), Aron Price (AUS), Cam Burke (CAN), Ted Brown (CAN), Dave Bunker (CAN)
72 - Alex Cejka (GER), David Hearn (CAN), Barrett Jarosch (CAN), Mike Weir (CAN), Chris Ross
73 - Jeff Puska, Henrik Bjornstad (NOR)
74 - David Lutterus (AUS), Ben Boudreau (CAN)
76 - Jim Rutledge (CAN)
78 - Lee Beon-yeong (CAN), Brian Davis (ENG)