PHOENIX (AP) -- Top-ranked Yani Tseng played a seven-hole stretch on the back nine in 7 under and finished with a 7-under 65 on Thursday for a share of the first-round lead with Hee Young Park in the LPGA Founders Cup.
Tseng birdied the 11th, 13th and 14th holes, eagled the par-5 15th, and birdied the 16th and 17th. She had a 4-foot try for another birdie on 18, but pulled her putt just left.
"I tried too hard on the last hole," Tseng said. "I think it's harder at the end because you are trying, you're saying, 'Oh, I have three, I have four.' And you want to go five, six, seven, and every hole is harder. You're just trying harder and harder."
Park closed with a bogey on the par-4 ninth for her 65.
"Most of the shots were perfect," the South Korean player said.
Jiyai Shin opened with a 66, and second-ranked Na Yeon Choi was another shot back along with Karen Stupples, Pernilla Lindberg and Hee Kyung Seo in the tour's first U.S. event of the year after stops in Australia, Thailand and Singapore.
Tseng successfully defended her LPGA Thailand title in February for her 13th LPGA Tour victory. The Taiwanese star led the tour last season with seven victories -- including major victories in the LPGA Championship and Women's British Open -- and finished the year with 12 worldwide titles.
Playing in the late afternoon with the temperature in the low 80s in perfect conditions at Wildfire Golf Club, Tseng holed a 9-foot putt on the 485-yard 15th after fading her 219-yard approach with a rescue club to the middle pin placement.
"It was a little fade, a little cut there," Tseng said. "It was just a little crowd, so I didn't know if my ball was close or not. But I had a good shot, and it was like 9 feet, and a pretty straight putt."
On the par-4 16th, her short iron shot to the elevated green spun back to 8 feet to set up a birdie. She then hit to 3 feet on the par-3 17th for her final birdie.
"I just hit it one shot at a time, because I don't even know what hole I am on," Tseng said. "I just really focus on one shot at a time, try to hit a good drive, get a good second shot and make good putt."
She played the first 10 holes in even par, countering a bogey on the fourth with a birdie on the par-5 fifth.
"First nine, I was missing a few putts," Tseng said. "But I kept telling myself, 'Just be patient.'"
Park won the season-ending Titleholders last year for her first LPGA Tour victory. She birdied all four par-5 holes, and holed a 15-foot birdie putt on the par-4 eighth -- her 17th hole -- to get to 8 under.
"I played really good on the fairway," Park said. "I hit the fairway and then green. Lucky thing was most putts, birdie putts, were uphill. So, that's why I just hit it aggressive."
Shin birdied three of her final five holes in her bogey-free round.
"The weather was perfect this morning, no wind, and the greens were soft," Shin said. "I know this course is pretty tough. Desert course is always tough because the bounce, and the rough is pretty tough. I just more focus to the accuracy with my shot."
After winning eight LPGA Tour titles in a three-year stretch, Shin failed to win last season. In a bid to shake things up, she has a new blonde hairdo.
"A lot of Asian players play here. They're black or dark brown, so I wanted to make like fresh," the straight-hitting South Korean said,
Defending champion Karrie Webb was in a group at 68 that included Kraft Nabisco winner Stacy Lewis, U.S. Women's Open champion So Yeon Ryu, Cristie Kerr and Ai Miyazato. Lewis birdied the par-5 fifth -- her 14th -- to top the leaderboard at 6 under late in the morning session, but had a double-bogey 6 on No. 8.
Stupples had surgery last week to remove an ovarian cyst and polyps. She withdrew from the pro-am Wednesday and was worried about being able to play Thursday.
"I went through the warmup," the English player said. "Everything felt great on the warmup and I said, 'Let's give it a go.' So, here we are."
She lost 21 pounds before the start of the season.
"It got to the point last year where I was over in Malaysia and really struggling playing in the hot weather and the temperatures," Stupples said. "We play so much overseas and a lot of high temperatures, and I really felt like the weight I was at was holding me back from achieving what I wanted to do. ... If you're not carrying an extra 20 pounds around, it has to make a huge difference."
DIVOTS: The winner will receive $225,000 from the $1.5 million purse. Last year in the inaugural RR Donnelley-sponsored event, the players competed for a mock purse and charity donations. ... Angela Stanford, coming off a playoff victory Feb. 26 in Singapore in the HSBC Women's Champions, opened with a 75. ... The tour will be in California the next two weeks for the Kia Classic and Kraft Nabisco.