FRANCE 11 Sept 2015, (AFP) - Lee, the halfway leader, recovered from dropping shots at the first two holes to post a 70 and she led by a shot from American Lexi Thompson (66) with Ko and Morgan Pressel another shot back in joint third on eight under.
For Ko, 18 years and four months, it is the last chance to surpass Pressel, who was 18 years and ten months when she triumphed at the 2007 Kraft Nabisco Championship, and become the youngest ever winner of a women’s major.
New Zealand's world number two made her move with a terrific round of 67, the only blemish coming with a bogey at the tricky final hole. The round ended in rain and wind and she bunkered her second shot and then failed to get up and down.
"It wasn't the easiest, conditions," acknowledged the player who made it to world number one at the start of the year.
"But it was a very solid round. I'd love to be about five shots ahead, but I'm happy with my position. It's a good place to be going into the last round."
Pressel was sharing the lead with playing partner Lee playing the last, but she hit her second shot into water and ran up a costly double-bogey six and had to settle for a 70.
For Lee, it was a great comeback from a miserable start. She got back to level par for the round by the turn with birdies at the fifth and ninth and then holed a raking 20-foot birdie putt at the 12th.
She dropped a shot at the 14th as the rain began to fall, but made a great up and down birdie at the long 15th and, at the 18th, she holed a ten foot par putt to stay ahead of the field.
For the 22-year-old, whose only LPGA win came in the Mizuno Classic at the end of last year, leading a major is a whole new experience.
"Tomorrow (Sunday) will be the first time that I've been in the last group in a final round and that makes me excited," said Lee. "I was really happy to make that putt at the last and I'm going to enjoy it tomorrow and, hopefully, not be too nervous."
With bad weather forecast, the organisers have decided to make it a two tee start and earlier times for the final day. "That pleases me," continued the leader. "I wont have so long to hang around.
"Today I bunkered my tee shot at the first and dropped a shot and then bogeyed the second. But I wasn't too worried. There were still 16 holes to go."
Leading scores after the third round of the USLPGA Evian Championship (par 71) on Saturday:
203 – Lee Mi-Hyang (KOR) 66 67 70
204 – Lexi Thompson (USA) 66 72 66
205 – Lydia Ko (NZL) 69 69 67, Morgan Pressel (USA) 69 65 71
206 – Amy Yang (KOR) 72 66 68, Feng Shanshan (CHN) 68 68 70, Nicole Broch Larsen (DEN) 68 67 71
207 – Ji Eun-Hee (KOR) 67 73 67, Lee Il-Hee (KOR) 71 67 69
208 – Lee-Anne Pace (RSA) 71 72 65, Minjee Lee (AUS) 68 72 68
210 – Gerina Piller (USA) 67 75 68, Charley Hull (GBR) 70 70 70, Karine Icher (FRA) 71 68 71, Pornanong Phatlum (THA) 67 71 70
211 – Pernilla Lindberg (SWE) 70 73 68, Jennifer Song (USA) 70 72 69, Lee Mirin (KOR) 71 71 69, Park In-Bee (KOR) 72 69 70, Michelle Wie (USA) 75 66 70
212 – Thidapa Suwannapura (THA) 75 70 67, Emily Pedersen (SWE) 73 71 68, Juli Inkster (USA) 76 68 68, Ko Jin-Young (KOR) 69 73 70, Alison Lee (USA) 70 70 72, Kim Sei-Young (KOR) 68 71 73, Lin Xi Yu (CHN) 71 68 73, Kim In-Kyung (KOR) 71 67 74
213 – Choi Chella (KOR) 72 72 69, Stacy Lewis (USA) 73 70 70, Candie Kung (TAI) 71 71 71, Kim Hyo-Joo (KOR) 73 69 71, Haru Nomura (JPN) 70 69 74
214 – Ayako Uehara (JPN) 74 70 70, Lee Min (KOR) 68 74 72