South Korea's Sei Young Kim leads the LPGA Shanghai tournament by one stroke at the midway point after shooting a five-under-par 67 on Friday.
Kim made six birdies, including four straight from the sixth hole, to move to 10-under.
The world No.15's only blemish was a bogey on the par-4 15th.
American Danielle Kang (68) and overnight leader Ariya Jutanugarn of Thailand (69) were leading the chasing pack.
Kang's compatriot Angel Lin eagled the par-5 17th before carding the round of the day - a seven-under 65 which leaves her clustered in a tie for seventh at six-under.
Australia's world No.5 Minjee Lee added a two-under 70 to her opening round 68, a double bogey on the second took some gloss of her round.
Su Oh was two shots further back in a share of 12th after a 71 while opening round strugglers Sarah Jane Smith and Katherine Kirk improved significantly.
Smith managed a six stroke upgrade with a 68 featuring five birdies to improve to two-under; Kirk shaved four shots of Thursday's effort to sign for a 70 and be even par for the tournament.
