PORTLAND, Ore. -- Pornanong Phatlum of Thailand had the hottest putter -- and round -- on a day that produced rain, thunder, lightning and torrid scoring at the LPGA Safeway Classic.
Of the 142 players competing in the $1.3 million event, 98 broke par at Columbia Edgewater Country Club.
Phatlum fired an 8-under-par 64 to take a one-stroke lead over Lexi Thompson.
"I'm feeling very good with the golf course. I like the course. Very nice," said Phatlum, 23, who hasn't won on the LPGA Tour this season but ranks 26th on the money list and has two top-three finishes.
Phatlum changed putters before the opening round at Portland, and she took a better liking to her newest club after it brought her 10 birdies. She missed six greens on the tree-lined course but needed only 22 total putts.
"I was not putting good last week," she said, adding, "I made almost everything (Thursday)."
Phatlum overtook Thompson, who fired a 65 and ended up with sole possession of second place.
Thompson, an 18-year-old from Coral Springs, Fla., had an eagle and six birdies. She played the four par-5s in 4 under.
Germany's Sandra Gal and Americans Cristie Kerr and Lizette Salas share third at 66. Next came 14 players at 67, a group that includes world No. 2-ranked Stacy Lewis, former world No. 1 Yani Tseng, 2010 Safeway Classic winner Ai Miyazato, Michelle Wie and Hall of Famers Juli Inkster and Se Ri Pak.
The field has nearly 90 of the top 100 money-winners in 2013, although world No. 1 Inbee Park withdrew Tuesday because of illness and No. 11 Paula Creamer pulled out before her tee time Thursday, citing personal reasons.
Most of the players took advantage of soft conditions created by early-morning rain, thunder and lightning. The start was delayed by an hour, and the tour instituted lift, clean and place rules on the wet fairways.
"It was especially important to hit the fairways," Lewis said. "You could at least give yourself a good lie."
Thompson, who turned pro when she was 15, hit 15 greens on the 6,454-yard layout and credited her iron play for her low score.
"I have been working on tightening up my shots, even with my driver," she said. "I think this is the best my game has ever been. I have been nonstop working on my game, trying to improve little things, and I think it's showing."
Thompson is looking for her second LPGA victory. She won the Navistar LPGA Classic in September 2011.
Her eagle came on the 463-yard seventh hole, after a drive into the right rough.
"I hit like a three-quarter 6-iron and hit pretty far short, and it rolled all the way up to about six feet above the hole," she said.
Thompson said she is now bouncing back emotionally from the disappointing U.S. loss to Europe two weeks ago in the Solheim Cup in Colorado.
"A few days after Solheim Cup were pretty tough," she said. "Those few practice rounds I was definitely not into it."
Gal, 28, former University of Florida player, also has one career LPGA win but didn't earn a spot on Europe's Solheim Cup team.
"I've been playing really well recently. I just haven't been making a lot of putts," she said.
Gal said she is aiming to play well enough between now and then to make the European squad when the 2015 Solheim Cup takes place in her home country.
"Being part of that would be just unbelievable," she said.
Lewis, gunning for her fourth LPGA win of the year, said she hit some shaky shots toward the end, but she didn't have a bogey.
"It's about as easy of a 67 as you can get," she said. "(The greens were) so soft, you are just playing target golf. I love it."
Wie, who has two tour victories but none since 2010, was 5 under through 10 holes, then had to settle for eight consecutive pars.
"Just didn't make a lot of putts," she said. "The greens were a little bumpy with the greens so soft. Just left myself a couple of tricky ones. I hit them well, I putted well, had good speed. Hopefully tomorrow I can get back on the birdie train."
Other scores of note: world No. 3 Suzann Pettersen, Natalie Gulbis and Jiyai Shin are among a crowd of 15 players at 68; and Morgan Pressel and Karrie Webb are among 16 golfers at 69.
Gulbis aced the 166-yard second hole.
Defending champ Mika Miyazato opened with a 71.