Park turned in a bogey-free, 6-under 66 at the Aviara Golf Club for a one-shot advantage over LPGA Hall of Famer Karrie Webb and Caroline Hedwall.
Tseng overslept Wednesday and missed the starting time for her pro-am pairing. Under LPGA Tour rules, anyone failing to show up for the pro-am event is not allowed to play in that week's tournament.
Lewis, in her first week with the No. 1 ranking, a 2-under 70 and was tied for 16th place. She won the Founders Cup event last week, the first tour stop in the United States this year.