Catriona Matthew shot her second straight 4-under 68 to take a three-stroke lead after the third round of the Lorena Ochoa Invitational on Saturday.
The Scot, who won the 2009 Women's British Open for the last of her three LPGA Tour titles, had an 11-under 205 total at Guadalajara Country Club.
''I think I'm putting the ball better this year, being more consistent,'' Matthew said. ''I haven't made the mistakes that I have made in the last couple of years. More bad shots the last years. This year in general I've been more consistent and pitching the ball better, so makes it easier when you're on the fairway.''
She played the first 52 holes without a bogey before dropping a stroke on No. 17 Saturday.
Norway's Suzann Pettersen was in second place after shooting a 71. Defending champion I.K. Kim of South Korea (70) was another stroke back, along with Anna Nordqvist of Sweden (73).
''I'm delighted to be in the lead,'' Matthew said. ''I would rather be three shots in the lead rather than three behind. I.K., Suzann and Anna all back there, all capable of coming up from behind, so I'm going to have to go out there tomorrow and shoot something in the 60s, I think.''
Last year, Kim closed with a 64 to beat Pettersen by three strokes.
''Is this a course where you can shoot a low round and come from behind, I.K.?'' Pettersen joked with Kim in the interview room. ''Yeah, it is. It is. I witnessed it last year so, no, I mean, obviously if you get going, try to take advantage of so many par 5s. There are tough holes coming up, and with the greens firm, you never know what it's going to be, but you have to put a good number together tomorrow.''
Hall of Famer Juli Inkster, who had a share of the lead after the first two rounds in the 36-player event, was 5 under after a 75. The 51-year-old Inkster is trying to become the oldest winner in U.S. LPGA Tour history.
Michelle Wie, the 2009 winner, was 1 under after a 71, while top-ranked Yani Tseng was 3 over after a 74.
The tee on the par-5 18th hole was moved up 40 yards Saturday, cutting the hole from 521 yards to 481.
''I think it's good they moved it up,'' Pettersen said. ''I don't think you've seen a lot of birdies there today. I don't think you've seen a lot of eagles, so I don't think it really makes an overall difference on how the hole is played, but it gives us a chance.''