South Korea's Ryu Hae-ran birdied the first four holes on her way to an eight-under 64, seizing a one-stroke lead after Saturday's third round of the LPGA Canadian Women's Open.
Ryu, whose only LPGA title came in last October's Northwest Arkansas Championship, stood on 13-under 203 after 54 holes at Earl Grey Golf Club in Calgary.
"Really good start, yeah, that was a good thing," Ryu said. "I just think about, wow, this course is so tough and so many challenges."
American Lauren Coughlin, seeking her first LPGA title, was second on 204 after firing a 66 while playing alongside Ryu. "I played extremely well," Coughlin said.
"Hae-ran played an unbelievable round as well, but I felt like I hung in there really well and was able to go blow for blow pretty much most of the day.
"She was making everything there to start, so I was just trying to stay in my own bubble and not get too into what she was doing, which was hard when she's playing as good as she was."
Japan's Mao Saigo fired a stunning bogey-free 61, an 11-under par event record, to share third on 208 with American Rose Zhang.
American Jennifer Kupcho was in fifth on 209. World number 20 Ryu's sizzling start overtook Coughlin for the lead. Ryu also birdied the sixth and 10th holes and answered her lone bogey at the 12th with a birdie at 13 and an eagle at the par-5 14th.
"Mao was 11-under par, I said wow she had a crazy day. But I started five holes in 5-under, so I'm crazy too, I think. It's funny today," Ryu said.
"Really proud of myself but I have one more round and I'll just trust my shots."
Ryu was a runner-up at last week's Dana Open, her seventh top-10 effort of the season, and fifth at the Evian Championship two weeks ago. "Because of really good finish at final round last week I have more confidence for my everything for the golf," Ryu said. "Now I just trust myself and really good score and keep going I think."
Coughlin, ranked 38th, battled Ryu for the lead all the way, starting with back-to-back birdies and adding two more at the par-3 fifth and par-4 sixth.
She stumbled with a bogey at seven but responded with birdies at the par-3 ninth and par-4 10th, then answered another bogey at 12 with birdies at the par-5 14th and par-3 17th to finish one off the lead.
Coughlin had her best finishes so far this year at majors, sharing third at the Chevron Championship and placing fourth at Evian.
- Saigo stuns with 61 -
The shocker of the round was Saigo, who made birdies on all four par-5 holes, added two birdies each just before and after her one-bounce eagle from the fairway at the par-4 10th and had a birdie at the par-3 17th to leap into contention.
"In the middle of the round, I tried not to think about the score anymore and focus on each shot and when I finished the round I realized I had shot 11-under and I was very surprised," Saigo said through a translator.