EDMONTON, Alberta -- Lydia Ko was back on top of the Canadian Women's Open leaderboard.
The 16-year-old Ko, the winner last year at Vancouver Golf Club at an LPGA Tour-record age of 15 years, 4 months, shot a 5-under 65 on Thursday in perfect conditions at Royal Mayfair for a share of the first-round lead with Angela Stanford and Christel Boeljon.
Ko, the South Korean-born New Zealander, had six birdies and a bogey. She birdied the opening hole, though she figured that might be a bad omen.
"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," Ko said.
She felt some pressure entering the tournament.
"Because you're the defending champion, people are going to expect more," she said. "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.'"
Stanford rebounded after going 0-4 last week in the United States' Solheim Cup loss in Colorado.
"Try to take positives from it," Stanford said. "It's hard because I'm the only one that has to live with it. I'm the one that it's probably haunting the most. So it's been really hard. I thought about going home a few times. ... The best thing was for me to get back on the horse. I had to get out and play and I guess just try to put it behind me."
The Texan birdied five of the first 12 holes in her bogey-free round.
"I hit it really well today, really solid, and I've been hitting it solid," Stanford said. "Finally the ball found the bottom of the hole a little bit faster. I think if you can keep it in the fairways on this golf course, you'll have chances at birdie."
Boeljon had a hole-in-one with a 9-iron on the 126-yard 16th hole. The Dutchwoman also had a bogey-free round, playing Nos. 15-17 in 4 under.
"I only realized it by the lady that was behind the green that put her hands up, and I was like, 'I guess it's in.' We couldn't see with the sun. Everyone was high-fiving, so we got up to the hole, and we see it's in. It helps your score out a lot."
U.S. Solheim Cup teammates Paula Creamer and Cristie Kerr shot 66.
Top-ranked Inbee Park, a six-time winner this year, was another stroke back at 67 along with fellow South Korean star Na Yeon Choi, France's Karine Icher and Canada's Jennifer Kirby.
"The course dried out a lot, so it played a little bit shorter than it did in the practice round," Park said. "I was hitting a little bit shorter irons, so I was able to attack some pins and I was able to make more birdies than I thought I could have made out there. I putted really good out there today, so I feel really good about it."
Charley Hull, the 17-year-old English player coming off a strong performance last week in Europe's victory, had a 69 playing alongside Ko and Kirby. Hull bogeyed the final two holes.
"I played pretty solid," Hull said. "I just hit one on 17 and then I missed a silly little putt on 18. ... I'm feeling pretty happy with my game and just going to practice some short putts after for a bit."
Second-ranked Stacy Lewis opened with a 74, and later withdrew because of illness. The Women's British Open winner in her last stroke-play event, Lewis bogeyed five of her first seven holes.
"I played terrible all day," said Lewis, coming off the deflating U.S. loss in the Solheim Cup. "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 last week is still tough."
Before she withdrew, Lewis was asked if she had anything to work on heading into the second round.
"No, honestly I need to get away from it right now," Lewis said. "Probably the best thing I could do is walk away."