Dufner finished off a 2-under 70 Monday to match Kim (66) and Retief Goosen (67) at 15 under entering the final round at saturated Glen Abbey. Michael Letzig (66), Bob Estes (68) and Nathan Green (69) were 14 under.
Mike Weir, trying to become the first Canadian winner since Pat Fletcher in 1954, was 9 under after a third-round 69. On Sunday, he had a hole-in-one and took a penalty stroke for an infraction Saturday on the final hole of the second round.
Weirs ball moved before he played his second shot on the par-5 18th, but he was unsure whether he grounded his club or caused the shift. After calling for a ruling, he replaced the ball in its original location and took a one-stroke penalty.
Before Weir signed his scorecard, the penalty stroke was rescinded after he and the rules committee reviewed video and determined it was inconclusive whether he caused the ball to move. On Sunday, more video was reviewed, and Weir again assessed himself a one-stroke penalty for causing the ball to move, even though it was still inconclusive whether he addressed the ball.
Even though I dont think I did, I guess theres that gray-area possibility I could have, Weir said. So with that, I didnt feel comfortable myself not taking it.
Weir wasnt disqualified for signing an incorrect scorecard.
If a committee makes a decision or an error we can certainly correct it, said Dean Ryan, a Royal Canadian Golf Association rules official.
Weir used a 4-iron to ace the 200-yard fourth hole. The hole-in-one was the seventh of the tournament, the most since the PGA Tour began keeping extensive records in 1971. There were five in the 2004 John Deere Classic.