Vera Dushevina upset seventh-seeded Roberta Vinci of Italy 7-6 (4), 6-4 to advance to the second round of the Kremlin Cup on Monday.
The Russian rallied from 4-0 down in the first set and from 4-2 down in the second, winning four consecutive games to wrap up the match.
Earlier, Kaia Kanepi of Estonia defeated Italy's Sara Errani 6-0, 7-5 on her debut at the tournament.
In the men's opener, Teymuraz Gabashvili of Russia advanced to the second round with a 6-2, 6-4 victory over Karol Beck of Slovakia.
Janko Tipsarevic, runner-up in 2009, leads the men's draw of the 22nd edition of the event. Vera Zvonareva, who won in 2008, tops the women's field.