PATTAYA, February 21, 2014 (AFP) - Nordqvist remained at her overnight six-under for the tournament, one stroke clear of Spain's Azahara Munoz, Julieta Granada from Paraguay and Germany's Sandra Gal.
A further shot behind at the Siam Country Club in Pattaya, on four-under, were American duo Michelle Wie and Stacy Lewis.
Four players in joint sixth place on three under were Americans Jennifer Johnson and Angela Stanford, South Korean Ryu So-Yeon and Australia's Karrie Webb.
The battle for the world's top spot remained tight, with South Korea's Park-In-Bee, the world number one, and her main challenger Suzann Pettersen from Norway, both in joint 11th place on two-under, just four off the pace.
Nordqvist, whose three birdies were cancelled out by three bogeys, was pleased to retain her lead with an even-par round.
"I hit it really good. I just couldn't get any momentum or putts to drop," she said.
Adding to the difficulty were some tricky pin placements.
"There were some tough pins out there," she said. "A lot of them were on ridges and there's not a lot you can do."
The Swede was disappointed to finish with a bogey at the 18th.
"I hit a decent shot just a couple of feet from the hole and it spun all the way off the green."
However she remained upbeat.
"I'm happy with the way I'm playing and looking forward to the next two days."
Gal was very happy after shooting a 70 in the wet conditions.
"I'm pretty pleased with the day," she said. "I had a pretty smooth front nine with three birdies but the back nine played a bit tougher."
The German said her improved driving had given her a boost.
"I'm a little bit longer with my driver now so I can carry bunkers that I previously couldn't. That makes the course a lot easier."
Granada, whose 68 was the joint lowest score along with Munoz, said the wet weather made things interesting.
"We had a whole lot of rain on the front nine so I had to concentrate."
The Paraguayan was impressed with the course, however.
"I like the course. You have to play well and hit good shots and that's what I did today."
There is no cut in this tournament and with a crowded leaderboard the event is set for an enthralling weekend.
Leading second-round scores on Friday at the Honda LPGA Thailand tournament (par 72):
138 - Anna Nordqvist (SWE) 66-72
139 - Azahara Munoz (SPA) 71-68, Julieta Granada (PAR) 71-68, Sandra Gal 69-70
140 - Stacy Lewis (USA) 71-69, Michelle Wie (USA) 67-73
141 - Karrie Webb (AUS) 71-70, Ryu So-Yeon (KOR) 69-72, Jennifer Johnson (USA) 68-73, Angela Stanford (USA) 68-73
142 - Brittany Lang (USA) 73-69, Lydia Ko (NZ) 72-70, Jenny Shin (KOR) 72-70, Park In-Bee (KOR) 71-71, Caroline Hedwall (SWE) 69-73, Suzann Pettersen (NOR) 69-73, Lexi Thompson (USA) 68-74
143 - Thidapa Suwannapura (THA) 73-70, Cristie Kerr (USA) 71-72, Feng Shanshan (CHN) 71-72, Gerina Piller (USA) 70-73, Morgan Pressel (USA) 70-73,
144 - Mariajo Uribe (COL) 75-69, Ai Miyazato (JPN) 74-70, Pak Se-Ri (KOR) 72-72, Dewi Claire Schreefel (NED) 71-73, Pornanong Phatlum (THA) 71-73
145 - Tseng Ya-ni (TPE) 72-73