Suwannapura, who has three top-10 finishes in 120 career LPGA Tour events, birdied five of the final six holes, including the par-5 18th at Highland Meadows. The Thai player had her last top-10 finish in 2014 at the Kingsmill Invitational. Her best performance this season was a tie for 18th three weeks ago in Arkansas.
Seven players, including defending champion I.K. Kim and former No. 1 Yani Tseng, were a stroke behind at 66.
Sei Young Kim, who shot an LPGA Tour-record 31-under 257 to win last week's event in Wisconsin, was four shots back.
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