Kazakhstan's Galina Voskoboeva was upset by Serbian qualifier Vesna Dolonc in three sets in the first round of the Kremlin Cup on Tuesday.
The world No. 160 was demolished in the first set but was able to turn things around and score 1-6, 6-1, 6-4 comeback win.
Moscow resident Dolonc will meet the winner of the clash between Romania's Simona Halep and sixth seed Nadia Petrova in round two.
Earlier, reigning champion Dominika Cibulkova came back from a set down to defeat Ekaterina Makarova 2-6, 6-4, 6-2 and set up a second-round match with Bulgaria's Tvsetana Pironkova.
World No. 44 Pironkova pulled off a surprise 6-0, 7-6 win over illness-hit U.S. No. 2 Varvara Lepchenko.