Karen Stupples of England chipped in a 35-foot birdie on the 18th hole to finish with a 5-under 67 and a two-shot lead after Saturday's second round of the 54-hole Grand China Air tournament.
Successive rounds of 67 had Stupples at 10-under 134 going into the final round.
American Laura Diaz, who led after a first-round 63, stumbled to a 73 _ 8-under for the tournament _ with four bogeys on the last five holes.
Louise Friberg of Sweden shot a 69 to move to 7-under, three off the lead. Three other players were four shots back: Shi-hyun Ahn of South Korea (68), American Christina Kim (68) and Candice Kung of Taiwan (69).
Both leaders struggled with a 45-minute rain delay when on the back nine and found it difficult to regain their rhythm at the West Coast Golf club on the southern Chinese island of Hainan.
An early 15-minute rain delay proved little bother, but the 45-minute suspension a few hours later sent many of the scores soaring in the LPGA's first tournament in China.
Minutes after the play resumed following the second deluge, Stupples dropped a 10-foot putt on No. 13 to go 11-under. Still leading, Diaz failed to go 13-under on No. 13, missing a 6-foot putt for birdie.
That seemed to ruin her round. She slipped to 11-under with a bogey at 14 and had bogeys on the next two holes. She saved par at the 17th, but had a bogey again on the final hole with a poor approach on her second shot.
Playing a group ahead of Diaz, Stupples also had late problems, with bogeys on 15 and 17. But she saved her round with the chip-in on the 18th.
Rookie Yani Tseng of Taiwan, who won the LPGA Championship this season as a 19-year-old, carded a 67 and was in a group of eight players five strokes off the lead.
Shanshan Feng, the only Chinese playing on the LPGA tour, shot a 73 and was nine strokes behind.