PORTLAND, August 31, 2013 (AFP) - Pornanong's two day total of 14-under 130 broke the previous 36-hole tournament record at Columbia Edgewater Country Club and left her one stroke in front of Norway's Suzann Pettersen, who carded a nine-under 63 for 131.
Pettersen jumped from a tie for 20th to second place, one shot in front of Germany's Sandra Gal who notched her second straight 66. German rookie Caroline Masson was alone in fourth on 133 after a second-round 64.
Pornanong, who won the unofficial HSBC Brasil Cup last year, holds the 36-hole lead for the first time as she seeks her first official win in five years on the LPGA Tour.
The 23-year-old had six birdies without a bogey.
"I played this good before, but this is the first tournament that I felt really good and really confident, so I've played really good, better than I have done before," she said. "I'm more confident and everything is better than I have before."
Although she has yet to win on the LPGA Tour, Pornanong has seven professional victories on the Ladies Asian Golf Tour and Ladies European Tour. She's keen to add an LPGA title to her resume.
"I really do want it, just at least one tournament," she said. "I just want to win it. I'm going to have a lot more confidence. I'm going to feel a lot better about my game. I can play easier golf, just going smooth, not to have a lot of pressure on myself, just to keep it going."
Pettersen made her big move with a round that featured nine birdies without a bogey. She birdied five of her first nine holes and said her putter was key.
"It was a great round on the greens," Pettersen said, adding that she benefited from her pairing with European Solheim Cup teammate Beatriz Recari.
"I kind of fed off Beatriz's start," Pettersen said. "She had five pretty quick birdies. It was kind of nice to get everyone going early... I pretty much made every good look that I had. One of my better putting performances here."
Masson, who is chasing Moriya Jutanugarn for the LPGA's Rookie of the Year Award, can pass the Thai player with a finish of 19th or better. Moriya missed the cut after rounds of 73-71.
Masson, however, said she wasn't focusing on the award.
"I've been happy with my season so far," she said. "I kind of did everything I wanted to. I played Solheim and I kept my card... There's no pressure for me really. I can only surprise, I guess, and that's my goal for the next two days is to keep doing what I'm doing right now, just have fun."
Leading second-round scores on Friday in the LPGA Safeway Classic (USA unless noted, par-72)
130 - Pornanong Phatlum (THA) 64-66
131 - Suzann Pettersen (NOR) 68-63
132 - Sandra Gal (GER) 66-66
133 - Caroline Masson (GER) 69-64
134 - Sandra Changkija 68-66, Cristie Kerr 66-68, Lizette Salas 66-68
135 - Pak Se-Ri (KOR) 67-68, Tseng Ya-ni (TPE) 67-68, Lexi Thompson 65-70
136 - Han Hee-Won (KOR) 71-65, Chella Choi (KOR) 70-66, Choi Na-Yeon (KOR) 70-66, Karrie Webb (AUS) 69-67, Kwak Min-Seo (KOR) 69-67, Shin Ji-Yai (KOR) 68-68, Brittany Lang 68-68, Natalie Gulbis 68-68, Heather Bowie Young 67-69, Juli Inkster 67-69
137 - Beatriz Recari (ESP) 71-66, Mina Harigae 69-68, Morgan Pressel 69-68, Ji Eun-Hee (KOR) 67-70, Ai Miyazato (JPN) 67-70, Stacy Lewis 67-70, Sydnee Michaels 67-70