It was the first competition for Sagström and Anna Nordqvist since they three weeks ago won the Solheim Cup with Europe in Ohio.
For Nordqvist, it is already finished golfing after rounds of 71 and 74 strokes, a total of three over par.
For Sagström, it looks all the more fun before the final round.
The Swede was responsible for a super sprint on Saturday.
After making three bogeys on his first seven holes, Sagström went the last eleven holes a full eight under par - after two eagles and four birdies.
Rounds 70 and 66 strokes give six under par in total, and she shares 24th place with, among others, Dani Holmqvist.
Minjee Lee, Australia, and Nasa Hataoka, Japan, lead at -2.
Hataoka made a hole-in-one on his second round.