Two late bogeys have taken the gloss off an otherwise promising round for Australia's world No.9 Minjee Lee in the Women's PGA Championship.
Lee made a flying start to the third women's major of the year, carding four birdies during her opening nine holes.
The Perth prodigy turned in 32 and climbed further up the leaderboard with a birdie at the par-4 first hole which was Lee's 10th.
But a run of five-straight pars was broken with bogeys on the seventh and ninth holes as she slipped to three-under par 69 for a share of 10th place.
Lee finished a shot ahead of Karrie Webb as the LPGA Tour veteran chases an eighth major win.
Webb wound back the clock to produce one of the highlights of the opening round with an eagle at the par-5 fifth hole.
She is in a tie for 15th at two-under par.
Compatriots Sarah Jane Smith and Su Oh carded one-over par 73s while Rebecca Artis finished with a two-over par 74.
Park Sung-hyun bounced back from a poor performance in the previous major to take a one-shot lead.
Park, among several long hitters who revelled in soggy conditions, carded six-under-par 66 on a Kemper Lakes course that was drenched by rain earlier in the week.
Four weeks after missing the cut at the US Women's Open, where she was defending champion, the South Korean was more assured, particularly on the greens, as she gathered six birdies.
Americans Jessica Korda, Brittany Altomare and Jaye Marie Green and Canada's Brooke Henderson were tied for second on 67.