South Koreans In Gee Chun and Sung Hyun Park shot 8-under 63 on Thursday to share the first-round lead in the Evian Championship, the last of the LPGA Tour's five majors.
Shanshan Feng, China's Olympic bronze medalist, shot a two-under 69 to move into sole possession of third place at 13 under.
Rookie In Gee Chun posted a super 66 to edge ahead of the field at the halfway stage of the Evian Championship on Friday, the final major of the season. Ko said in her pretournament news conference.
"A lot", was her simple response when asked how many time the two had played together. "Because it puts too much pressure on me".
Charley Hull, who played alongside Matthew for Team GB at the Olympics, looked set to finish high on the leaderboard when she covered the first 15 holes in four under par. Discussing what to do with her caddie for several minutes, Chun decided against a drop shot and declared it unplayable, going back to where she took the shot from and incurring a two-stroke penalty.
"But, from the tenth, I wasn't hitting fairways".Chun, won last year's U.S. Open victor, credited her commitment to her reads on the greens and her playing partners, Ariya Jutanugarn and Julia Engstrom for her strong play.
But it will be hard to match her performance previous year, let alone improve it. Since winning the Cambia Portland Classic on June 30, the 19-year-old (one of seven under the age of 25 in the world's top 10) has fared no better than a tie for 14th in five starts.
"Even though I am not in front, I feel good".
"Before the round, I felt really nervous today. but I could see the putting lines very well and I was so good rolling the ball on those lines".
"The game plan for tomorrow [Sunday] is just to keep doing the same thing", said Chun, who is in her first year on the LPGA Tour. "I like to know what position I am in and what I need to do down the stretch or if I'm around the cut line what I need to do coming home". Ko won this event by six strokes a year ago when she finished at 16-under par, but each of the previous two winners won by two strokes or fewer.
One notable absentee at Evian this year is Park, who is getting rehabilitation on her troublesome thumb.