With the overnight leader having his hands full with Quatre Domaines GC for the first time this week, Heffernan took advantage with a 3-under 69 during Saturdays third round. He will take the outright lead into the final day for the first time with an 18-under 198 total, one shot better than American Brian Guetz (69).
Travis Johnson fired a 64 to leap into a tie for third with Canadians Darren Griff (69), Chris Baryla (67) as well as three-time Tour winner Rob Johnson (70).
Looking to build on rounds of 61-67, Mackenzie, a former amateur standout at the University of Washington, ran into a wall Saturday with a 4-over 40 on his front nine, eight shots worse than Heffernan, being the catalyst for a 74.
Saturday marked the first time this week that the lift, clean and place rule was not in effect. Heavy storms early in the week left Quatre Domaines waterlogged and tournament officials decided to play it down after the second round, suspended by darkness Friday night, wrapped up early in the morning. Brisk winds in the afternoon also prevented any of the leaders from running away from the pack.
A total of 64 players were 5-under 139 or better to play on the weekend, making it the lowest cut number relative to par in Canadian Tour history.
Guetz held a one-shot lead playing the par-4 ninth but gave that one back with a bogey. Playing in the next group, Heffernan knocked it within 20 feet on nine and made birdie to take over top spot on the leaderboard.
Heffernan stayed one up on the back until Griff converted back-to-back birdies on 15 and 16 to pull even. Facing a 93-yard third shot on the par-5 closing hole, Heffernan tape-measured it to two feet to set up a tap-in for the outright lead.
At the start of the day, I didnt think 69 would hold up, Heffernan admitted. I hit the ball great but hardly made anything. We (the leaders) stalled a little bit but it worked out.
Heffernan and Griff have enjoyed an almost carbon-copy run through Canada this summer. In his last four starts, Griff has been inside the top ten three times including a second-place showing to Josh Habig two weeks ago at the MTS Classic. Dating back to the Diablo Grande California Classic in April, Heffernan has four top eight showings in five events.
Griff continued his solid play Saturday and managed a bogey-free round until the par-3 17th. It was his first bogey since his second hole Thursday. On 18, he just missed a 12-footer that would have seen him in the house with a share of the lead.
Not playing lift, clean and place sure made this a different golf course, said Griff, referring to the low scores through the opening two days. I really didnt do anything special. I made some solid par putts to put myself in position again. But it is what it is. Its golf. We should have a lot of fun tomorrow.
Guetz will be looking for his second win of the season in Montreal and knows the $32,000 winners cheque would likely him from fourth into the top two on the Rolex money list. Quatre Domaines is biting back for the first time this week, which should make for a wild finish.
Not playing ball in hand is like two shots for every player, he said. The course is starting to get hard and the greens are firming up. I think you will see a whole different course tomorrow.
Its shaping up to be a great finish. Hopefully we can have some fun and give them a show.
Johnson made the biggest charge on moving day with an 8-under 64 despite not making it to the course until 20 minutes before his tee time.
I didnt know Montreal was this much fun, laughed the 25-year-old. We stayed up a little too late last night, but it worked out well, didnt it?
One year ago Peter Tomasulo, Johnsons friend and fellow Long Beach, Calif. native, won this event and followed that up with a triumph at the Nationwide Tours Alberta Classic.
Johnson would like nothing better than a little Golden State karma.
I wouldnt mind following Peters little stretch, he added. Ill try to catch that draft from my buddy from Long Beach and see where I end up.
There will also be a little extra incentive for Heffernan and the three other Canadians inside the top ten heading into Sunday. Since Matt McQuillan won the Telus Edmonton Open last summer, American-born players have swept the next 13 events through the MTS Classic.
The Maple Leaf is flying high in LaBelle Province and Heffernan wants nothing more than to grab his first Tour win to snap the U.S. run.
Its always great to see Canadians win, especially up here in Canada, he added. Ill go out there and do the same things I have done the last three days. You have to make birdies when you have the chance. Ive been playing well most of the year and I think Im ready.