32-year-old Piller, without a win to date in her seven-year career on the LPGA Tour despite being a two-time Solheim Cup team member, recorded an opening round of 63 to lead Park and Taiwan’s Peiyun Chien.
"I feel like my game has been pretty good all year," said Piller. "I just haven't been able to put four rounds together. Just hopefully I'll peak at the right time, and I feel like my game has been good all year, it's just trying to put it all together.
At 6 under and two behind Piller are the rising Indian star Aditi Ashok, In Kyung Kim and American Kelly Shon.
While Piller’s round was impressive, that Park had committed to the event so soon after her historic win last week in New Jersey and performed so well is a reflection on not only her great talent but her significant constitution.
"My feeling today was so awesome," said Park. "It was a good start after the major championship winning, and first of all, I need to focus more on the Marathon Classic and want to keep my happiness behind from now on."
Rookie Chien has missed five of her last six cuts so her turnaround was surprising although she put it down to focusing more on playing the game rather than getting too bogged down with technique.
I was doing well today because I changed my playing because I'm always thinking the swing on the golf course,” said Chien. “Today I just played freely, tried to find some feeling and play, and it's worked, so I'm very happy.”
Other favoured performers aside from Park were Amy Yang who is in 33rd position at 3 under and defending champion Lydia Ko who is in 103rd position at 2 over and in 105th position.
Only two Australians are in this week’s field, led by US-based New South Welshwoman, Wendy Doolan, who opened with a round of 1 under on the relatively low-scoring layout.
Sarah Kemp is at 1 over and in 89th place.
DANIELLE KANG: SHORT IRON CONTROL
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