Hunter Mahan birdied the final three holes Friday for an 8-under 64 and a two-stroke lead after the second round of the Canadian Open.
Coming off a ninth-place tie last week in the British Open, the five-time PGA Tour winner had eight birdies in his bogey-free round at Glen Abbey to reach 13-under 131.
"I kind of built off last week," Mahan said. "I got some good things I'm doing with my swing and everything, and feel good about that. I'm just going out there and really trying to trust my game.
"Just allow things to happen and not get in the way of myself and be as present as I can and keep my head up and keep moving forward and just kind of letting my abilities and everything that I'm doing in my game, let it try to come out."
John Merrick was second after a 62. He tied the course record set by Leonard Thompson in 1981 and matched by Andy Bean in 1983 -- both when Glen Abbey played to a par of 71 -- and Greg Norman in 1986.
Merrick had an eagle and 10 birdies, playing the back nine in 6-under 31.
"It was a great day," Merrick said. "I got off to a good start, hit it over the green on 2 and chipped in for eagle, and that kind of calmed me down. ... I hit it well and made a lot of putts."
He won the Northern Trust Open in February at Riviera for his first PGA Tour title.
"I've had stretches of good play," Merrick said. "You know, it's tough out here. It's competitive. You've got to be on for four days, and I've had some good rounds here and there a couple days, and you just need to put four rounds together out here. My game has been feeling pretty good. Everything kind of clicked today."
Bubba Watson was 9 under after a 67.
"I haven't been in too much trouble," Watson said. "When I hit it in the rough I have a decent lie or miss it in the right spot so I can hit the green in regulation. I missed three greens in two days, so I'm just hitting my irons well, playing smart golf, and then I made a few putts."
Aaron Baddeley and Patrick Reed shot 68 to reach 8 under, and Tommy Gainey (64), Chris Kirk (69) and James Hahn (68) followed at 7 under.
Mike Weir was the top Canadian, following his opening 73 with a 67 to move into a tie for 26th at 4 under.
"It was a great day," Weir said. "It was one of those rounds that could have been really anything. I could have been 10 under pretty easily, I think. But played great, and it was exciting to do that for the fans. Yesterday was so dull, one birdie and nothing happening at all, so it was great to feel that kind of support out there and give them something to cheer about."
Pat Fletcher, born in England, was the last Canadian winner, taking the 1954 event at Point Grey in Vancouver. Carl Keffer is the only Canadian-born champion, winning in 1909 and 1914. Albert Murray, a Canadian also born in England, won in 1908 and 1913.
Mahan praised the course and the setup.
"The course is in great shape," Mahan said. "Tee to green it's fantastic. The greens are rolling pretty true. If you hit it well out here, par 5s, you can attack the par 5s. It's a fun golf course to play.
"I think they did a good job with the setup here because they could have grown the rough up and made it really difficult, and it's tough to come back from a major and play the next week, especially when it's a hard golf course. It's really a mental grind. But I think the golf course setup is fantastic because it's still playable but it's still difficult and still challenging."
