Jim Furyk shot a seven-under-par 63 to grab a share of the lead with Justin Rose after the opening round of the Canadian Open.
Furyk, the world's third-ranked golfer and a member of the United States Ryder Cup team, used an eagle on his third hole of the day as a springboard to his bogey-free round that included five birdies on the 6,946-yard Hamilton Golf and Country Club layout.
Furyk holed a 9-iron from 121 yards on the par-four, 236-yard 12th to break the professional course record set by Tommy Armour in 1930. He just missed the overall course mark of 62 held by amateur Warren Sye.
Rose bogeyed his second hole of the day but rebounded with three consecutive birdies to move into contention after the first round for a second straight week.
The Englishman trailed eventual winner Tiger Woods by a stroke after the opening round of last week's Deutsche Bank Championship and shared the lead with Robert Allenby after the second round before finishing in a tie for fourth.
A trio of players, Brandt Jobe, Frank Lickliter and Nathan Green, were a shot back at 6-under 64. Green also had an eagle in his round, at the par-5 550-yard 17th.
Jesper Parnevik heads a group of five players at 5-under that includes Arron Oberholser, Jonathan Byrd, long-hitting Bubba Watson and Sean O'Hair, who overcame a double-bogey on the 11th hole with birdies at number 16, 17 and 18.
Defending champion Mark Calcavecchia is at 4-under 66, overcoming a pair of early bogeys with four birdies coming in.
Vijay Singh, the 2004 champion here and the third-round leader at the Deutsche Bank before falling victim to Woods' closing 63, is at 68.
Canadian Mike Weir, the hometown favourite who treats this event as a major, managed just one birdie in a 1-over 71.
