OAKVILLE, Ont. -- Hudson Swafford birdied on No. 18 to take the clubhouse lead with a 7-under 65 on Thursday in the first round of the RBC Canadian Open.

Swafford two-putted on the par-5 18th to separate himself from a crowded top of the leaderboard on a rainy day that softened the fairways and greens of the normally firm Glen Abbey Golf Club.

"It's gettable. It's about as gettable as I've seen this golf course but it's in great shape," said Swafford. "The greens are perfect. So you can make some putts. I was just trying to give myself as many chances as possible; if the ball was 30 feet or two feet.

"That was the main concern today, just get it on the greens. Felt great with the putter. Really rolled it beautifully."

Because the rain stopped in the late morning it was expected that afternoon scores would be higher.

Six players shared second place at 5 under, including Tyrone Van Aswegen, James Hahn, Smylie Kaufman, K.J. Choi, Bubba Watson and Brandon Hagy.

Mackenzie Hughes of Dundas, Ont., was the low Canadian from the morning group, firing a 5-under 67 to enter a seven-way tie for eighth.

"If you hit it in the fairway, you can be aggressive," said Hughes. "The few fairways I missed, I was just trying to make par and you have to be a little bit defensive.

"All in all it was a great day. Probably could be a bit better but I made a couple nice par putts, too. Overall, happy with my start."

Jared Du Toit of Kimberely, B.C., was 1-under 71 on the day, while Mike Weir of Brights Grove, Ont., finished his round at even-par 72. There are a total of 17 Canadians competing in the national championship.