American Jason Dufner went one-under through six holes of the third round to top the leaderboard at the rain-plagued PGA Canadian Open on Sunday.

Third round play was suspended Sunday for good at 5:00 pm local time making it the fourth-straight day that rain and lightning have disrupted the $5.1-million event.

More than 10 centimetres of rain have fallen on the Glen Abbey Golf Club course in that time.

"None of the players can control what's going on," Dufner said. "I think everybody wants to get out there and play and compete and try to win this golf tournament."

Dufner moved to 14-under par and has a one-shot lead over Anthony Kim and Jerry Kelly. Kim completed nine holes and Kelly six on Sunday. No player got through more than 14 holes in the third round.

Organizers had hoped to get in 36 holes on Sunday but are now looking at Monday finish. It is the first time in the past 21 years the event has carried over into a Monday.

Five players, Michael Letzig, Retief Goosen, Bob Estes, Peter Tomasulo and Scott Verplank, share fourth place at 12-under par.

Dufner had rolled in one birdie and had five pars on Sunday.

Kim's abbreviated round included five birdies in a six-hole stretch while Kelly posted two birdies.

There is a chance the event could go into Tuesday or be reduced to 54 holes if the bad weather persists on Monday. The last PGA tournament shortened to 54 holes was the 2005 BellSouth Classic.

"Instead of reading the grain, you have to read the current out there," said Canadian Mike Weir.

Weir, who is at nine-under, posted a hole-in-one and was also caught up in a complicated ruling that involved his second shot on 18th Saturday.

Weir is seeking to become the first Canadian winner since Pat Fletcher in 1954.