Brooke Henderson remains in the lead at the Evian Championship, but a round of 65 from Ryu So-yeon on Saturday saw the South Korean move within two shots at the top of the leaderboard.
After back-to-back rounds of 64, Henderson carded a steady 68 on the third day in France, opening with a bogey before making four birdies and 13 pars to finish on 17-under overall.
Henderson, who won her first major at the Women's PGA Championship aged 18 in 2016, missed a chance to give herself an extra cushion as she slightly pulled a birdie putt on the 18th hole.
Ryu had managed a 67 and 66 on the first two days in Evian-les-Bains, and saw improvement again on Saturday as she carded eight birdies, despite also bogeying the fifth and 10th holes.
World number three Nelly Korda, who had been in second place overnight, struggled to replicate her positive start as the American carded an even-par round of 71, tied for sixth overall.
Sophia Schubert sits two shots further back in third after going round in 66, while Carlota Ciganda and Kim Sei-young are tied for fourth after carding 67 and 68 respectively.
World number one Ko Jin-young produced six birdies and two bogeys for a round of 67, sitting on 11-under-par in joint-sixth place heading into Sunday.
The only player to best Ryu's 65 was Albane Valenzuela of Switzerland, who produced an impressive round of 64 to move from tied for 30th to tied for 11th.