World No.1 Lydia Ko hopes to celebrate her 19th birthday on Sunday with yet another victory in the LPGA's Swinging Skirts Classic.
Set to begin play on Thursday (Friday AEST) at Lake Merced, the top-ranked Ko has won the event the past two years.
"I can't believe it's already my third year on the tour," Ko said on Wednesday.
"I feel like I'm getting old. There are girls younger than me. Last year and the year before, everybody was older. I feel like everything is changing really quickly."
Minjee Lee, the 19-year-old Australian who came from five strokes down on the final day to win the Lotte Championship last week in Hawaii, also has had success at Lake Merced, winning the US Girls' Junior four years ago.
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"It was my first time in America and I was really excited," Lee said. "I can't quite remember how the course was set up but it was really fun."
Ko has 12 LPGA Tour titles, the first two in the Canadian Women's Open as an amateur. She beat Stacy Lewis by a stroke at Lake Merced in 2014 in the inaugural event and topped Morgan Pressel in a playoff last year.
"When you come back to a place where you've played well and you feel the love you always love coming back," the New Zealander said. "Having so many great memories I'm excited for it to start."
She has two victories this season, taking the Kia Classic and major ANA Inspiration in consecutive weeks in Southern California.
"I love California," she said. "I love this West Coast swing. I wish I could live on the West Coast."
