American Kevin Na fired a nine-under-par 63 to seize the clubhouse lead in the first round of the $5-million PGA Canadian Open on Thursday.

The 25-year-old Na rolled in nine birdies over his final 12 holes to take a two-shot lead in the event which was suspended Thursday because of darkness.

Golfers had to endure an almost eight-hour rain delay, leaving 98 players on the course when the horn sounded, including many who had yet to tee off. The first round will resume Friday morning at the Glen Abbey Golf Club.

Canadian No. 1 Mike Weir got off to a strong start but stumbled on the back nine to finish at one-under 71.

South Africa's Retief Goosen fired a bogey-free seven-under 65, including an eagle to begin his round. Goosen is tied for second with Americans Joe Durant and Scott Verplank.

American Jimmy Walker is alone in fifth at minus-six. He completed 14 holes.

Trevor Immelman, who won the 2008 Masters, tried to make the most of his first start since May, but had to settle for a one-under 71.

Na, of Rancho Cucamonga, California, birdied five-straight holes to complete his round. On his second hole of the day he got into an argument with his caddie and said it actually helped him play better.

"I told my caddie, I said, 'I think I can get over the tree.' He said, 'there's no way you can get over the tree.' We sat and argued for a couple minutes," Na said.

"I said, 'I can do it.' He said, 'no, you can't.' He rarely says you can't do something, so he made me pitch out, and I ended up making a 15-footer for par that kind of kept the round going. And after that I started to back down and started catching fire."

Like Na, Goosen began on the No. 10 tee. He eagled the par-five 13th then followed it later with three consecutive birdies beginning with the 16th.

Defending champ Chez Reavie of the US is tied for 84th after a disappointing one-over 73.