Matthew holed birdie putts of 25 feet and 12 feet on her final two holes to move to 6-under 210, one stroke ahead of Meg Mallon, who had a solid 69. Only a bogey at 18 marred the round as Mallon mastered the difficult Summerlea Golf and Country Club course southwest of Montreal.
Another two shots back were Gloria Park and Se Ri Pak of South Korea, who were tied with Australian Michelle Ellis at 3-under 213. Charlotta Sorenstam of Sweden and Karrie Webb of Australia were at 214, one shot ahead of Michele Redman. First-round leader Kate Golden was one of three players at even-par 216.
The wind, a telling factor each round, played havoc again. Although it didn't gust as strongly as the 20 mph bursts on Friday, the top 11 players still combined for 32 bogeys on another warm, sunny day.
The forecast for Sunday's final round was calling for isolated showers and thunderstorms by late morning with wind gusts of 25 mph. Annika Sorenstam won last year's tournament by two strokes over Kelly Robbins on a soggy Sunday.
''Anybody within seven shots of the lead has a chance if the wind comes up,'' Ellis said. ''It's one of those courses.''
Park and Namika Omata of Japan, the only players who did not card a bogey on a second round that featured nearly 700 and 105 double bogeys, misfired quickly with three bogeys each on the front nine.
Park, who began the day in a three-way tie for the lead with Matthew and Ellis, quickly dropped with three bogeys in the first four holes. She rallied with four birdies before the turn, then bogeyed Nos. 12 and 14 to fall back.
''I'm still in good shape,'' Park said. ''You never know what's going to happen. You have to be patient. This course is so tough, but I have a chance.''
Omata wasn't so lucky. She had two more bogeys and only one birdie on the back side and was 1-over for the tournament after a 76.
Pak shot 68 and charged toward the top of the leaderboard with a strong finish. She started the day five shots behind and moved to 4 under after three consecutive birdies on the back nine. She missed a 7-foot putt for par at 17 for bogey and ended the day at 3-under.
''I was mad after that putt, but that's the way golf is,'' Pak said. ''There's still one day left and I feel good about it.
Full-field scores from the Bank of Montreal Canadian Women's Open