South Korean-born New Zealander Ko set an LPGA Tour record when she triumphed at Vancouver Golf Club at the age of 15 years and four months.
And the defending champion’s return to the West coast of Canadian started in a similarly positive fashion as she opened with a birdie on her way to shooting a five-under-par 65 to join Stanford and Boeljon at the top of the leaderboard.
“When I start off with a birdie I haven’t really played that well, so yeah, I was kind of nervous that I did make a birdie on the first,” the 16-year-old said.
“Because you are the defending champion, people are going to expect more. I called my dad a couple of days ago and he just said, ‘Relax. You can’t control everything. Just play the game that you want to play’.”
Dutchwoman Boeljon hit a hole-in-one at the 16th in a bogey-free round to help lift her to the top of the leaderboard while Stanford, who also posted a bogey-free round, roared back from a 0-4 win-loss record in last weekend’s Solheim Cup to get back on top.
US Solheim Cup team-mates Paula Creamer and Cristie Kerr both shot 66 to sit just one shot off the lead, while world number one Inbee Park is a shot further back after a round of 67, tied for sixth with Na Yeon Choi, Karine Icher, and Jennifer Kirby.
Ko was paired with another teenager in 17-year-old Charley Hull, part of Europe’s successful Solheim Cup team; the Brit also enjoying a promising start to the tournament to sit another two shots back from Park tied for 20th.
But world number two, and Women’s Open champion, Stacy Lewis endured a disappointing day as she struggled to a round of 74.
“I played terrible all day,” Lewis said. “I didn’t make any putts, I didn’t hit the ball very good and the start just didn’t help.
“I was tired out there. Mentally, I wasn’t in it. Just coming off (the Solheim Cup) last week is still tough.”