Chad Campbell fired nine birdies in a nine-under par 63 on Friday to grab a two-stroke lead in the US PGA Tour`s Canadian Open.
The American, in search of a fifth career title and his first since 2007, had a 36-hole total of 14-under par 130 and was two strokes clear of compatriot Brian Harman, who carded a 67 for 132.
"Never really felt like it was going to be a crazy round, which nine birdies -- I`m definitely happy with it," said Campbell, whose round was one stroke shy of the Glen Abbey record when played at par-72 -- posted by Greg Norman in 1986 and John Merrick in 2013.
Campbell birdied all four of the course`s par-fives. Although he has hit just 14 of 28 greens in regulation in the first two rounds, he needed only 25 putts on Thursday and 24 on Friday.
"It`s kind of weird because it happened with the par-fives," said Campbell, a former US Ryder Cup player. "Knocking them on in tow and two-putting. I made a couple of long putts, which always helps."
Canada`s David Hearn fired a 64 to share third place on 133 with American Johnson Wagner, who posted a 66.
If he can pull off the victory in his home open Hearn would become the second Canadian to win on tour this season, after Nick Taylor`s triumph in Jackson, Mississippi, back in November.
The last Canadian to win the Canadian Open was Pat Fletcher in 1954.
"If I continue to keep playing the way I am, I know I have a chance," said Hearn, who had eight birdies in his bogey-free effort. "I can`t control what Chad or any of the other players are going to do. But if I keep doing what I`m doing and stay focused on that, I like my chances."
Australian Jason Day, coming off a share of fourth place at the British Open at St. Andrews, was alone in fifth place on 134 after a 66.
The world number 10 highlighted his round with an eagle at the par-five 18th.
Although the weather-induced Monday finish at St. Andrews left Day with a short turnaround, he didn`t think fatigue would be a factor at the weekend.
"I`m driving it great," Day said. "I`d like to tune up the iron shots, but overall I`m hitting it good.
"Biggest thing for me is still trying to get as much rest as possible, especially coming off last week so that I can stay mentally sharp."