LOS ANGELES • Gerina Piller fired an eight-under 63 on Thursday to take a one-stroke lead over newly-crowned US Open champion Park Sung Hyun and Chien Pei-yun after the first round of the LPGA Marathon Classic.

Piller, chasing her first LPGA title, got off to a strong start at Highland Meadows in Ohio, with birdies at four of the first five holes.

Another birdie at the par-three eighth was followed by her lone bogey of the day at the par-four ninth. She added four more birdies on the back nine.

"Got off to a good start and got the putts rolling," the 32-year-old American said. "My ball-striking didn't feel as great coming into this weekend. But I just went out there and really trusted what I had and just brought it together."

South Korea's Park, who made her first LPGA win a Major championship when she lifted the US Women's Open last weekend, showed no sign of a let-down.

She fired seven birdies in a bogey-free round. Taiwan's Chien had eight birdies and a bogey in her 64.

"My feeling today was awesome," Park said. "It was a good start after winning the Major championship."

She added that there was no temptation to dwell on that victory and she was focusing on this week's tournament with last week's happiness "behind from now on".

Three players shared fourth on 65: India's Aditi Ashok, South Korean Kim In Kyung and American Kelly Shon. Lydia Ko, the former world No. 1 seeking her first win since lifting this trophy last year, opened with a 73 that included three bogeys and one birdie.

"I shaped my drivers pretty well, but the three times that I missed a fairway I wasn't able to make up-and-down from there," the New Zealander said. "Hopefully I'll be able to hit a few more fairways."

AGENCE FRANCE-PRESSE

LPGA MARATHON CLASSIC

Day 3: Singtel TV Ch115 & Ch209, tomorrow, 3am