Sweden's Anna Nordqvist and South Korea's So Yeon Ryu each birdied the final hole for a share of the second-round lead with Thailand's Pornanong Phatlum on Friday in the Lorena Ochoa Invitational.
Nordqvist and Ryu shot 5-under 67 to match Phatlum at 9-under 135 at Guadalajara Country Club. Phatlum, the first-round leader in the 36-player event, had a 69.
South Korea's Inbee Park was a stroke back along with Americans Lexi Thompson and Gerina Piller. Thompson had a 64 for the best round the first two days. Piller shot 65, and Park had a 68.
The top-ranked Park swept the first three major championships of the season and has three other LPGA Tour wins this season. She's winless in eight starts since the U.S. Women's Open in late June.
Second-ranked Suzann Pettersen and No. 3 Stacy Lewis were tied for ninth at 6 under.
Pettersen had a 68. The Norwegian player is coming off a successful title defence in the LPGA Taiwan, her third victory in her last five starts and fourth of the season.
Lewis shot a 66.
Michelle Wie had a 73 to drop into a tie for 20th at 2 under. She won the 2009 tournament for the first of her two LPGA Tour victories.
Defending champion Cristie Kerr was 27th at 2 over, following a 77 with a 67.
Tournament host Lorena Ochoa won 27 LPGA Tour titles before retiring in 2010.