She finished the round of 70 strokes, two under par, with five birdies and three bogeys. In total, Stark is now at -14.
It looked like the Swede would be out one stroke after the close trio but a bogey on the 18th hole left Stark two strokes up.
Leading the way are Thailand’s Jeeno Thitikul, China’s Ruoning Yin and Korea’s Haeran Ryu, all at -16.
The decisive round begins during the night towards Sunday, Swedish time.