ST. PETERSBURG, Russia (AP) -- Roberta Vinci secured her place in the quarterfinals of the St. Petersburg Ladies Trophy by beating Belgium's Yanina Wickmayer 6-2, 7-6 (2) on Wednesday.
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.
The Italian's quarterfinal opponent will be ninth-seeded Monica Niculescu of Romania or unseeded Timea Babos of Hungary.
Ana Ivanovic powered into the quarterfinals when her Russian opponent Margarita Gasparyan crumbled, winning 7-5, 6-2.
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.''
Ivanovic, who had a bye in the first round, will face either Russia's Elena Vesnina or Ukrainian Kateryna Kozlova in the quarterfinals.
The seventh-seeded Kristina Mladenovic of France lost in the first round after a two-hour fight with Laura Siegemund of Germany.
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.
Siegemund faces promising young Russian Darya Kasatkina in the second round after she beat Belgian Kirsten Flipkens 6-4, 5-7, 6-4.
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.