Vinci downs Wickmayer to reach St. Petersburg quarterfinals
Vinci, seeded second, served for the match at 6-5 in the second set but was broken by Wickmayer, who proved unable to put up the same resistance in the following tiebreak.
Ivanovic, seeded fourth, was 2-0 down in the second set before winning the next six games to take the match. Gasparyan had three break points on Ivanovic's serve at 2-2 but failed to take advantage, became frustrated, and never recovered.
"I really had to dig deep," Ivanovic said. "I'm really happy with the way I played today, especially in my first match."
Siegemund, who made the main draw as a lucky loser, took the initiative in the second set against Mladenovic to win 1-6, 7-5, 6-1.
Also, former Australian Open finalist Dominika Cibulkova of Slovakia made short work of Evgenia Rodina of Russia in the first round, 6-3, 6-0.
Copyright 2016 by The Associated Press
This story is from ESPN.com's automated news wire. Wire index