ANTWERP, Belgium -- Third-seeded Andrea Petkovic fought off eight match points to reach the quarterfinals of the Diamond Games tournament with a 6-7 (7), 7-6 (5), 6-2 win over local favorite Belgian Alison Van Uytvank on Wednesday.
In a marathon that lasted three hours and 20 minutes, the 103rd-ranked Van Uytvank came close to sealing a straight-sets win but Petkovic saved all eight match points in the 12th game of the second set and proved the stronger in the tiebreak.
Van Uytvank struggled to recover as her German rival jumped to a 4-0 lead in the decider. Spurred on by her fans, the 20-year-old Belgian managed to break again but Petkovic prevailed.
Earlier, Dominika Cibulkova made light work of qualifier Kateryna Bondarenko to reach the second round with a 6-1, 6-2 victory.
The sixth-seeded Cibulkova, who was playing in her first match since losing to Serena Williams in the quarterfinals of the Australian Open, broke her opponent twice in the first three games to set the tone for the match.
Bondarenko has recently returned to the tour after the birth of her first child and could not match Cibulkova's pace in the second set, dropping her serve three more times.
"I went into the match not expecting too much of myself, it was my first match in a few weeks and totally different conditions than Melbourne," said Cibulkova. "I practiced here for four days and my coach just told me to do my best and everything I did out there was really working."
Cibulkova will take on another qualifier in the next round after Indy de Vroome rallied past Tsvetana Pironkova, 5-7, 6-3, 6-3.
Eighth-seeded Karolina Pliskova and Monica Niculescu also progressed.
Pliskova got off to a strong start against Mirjana Lucic-Baroni, jumping to a 4-0 lead, but her 56th-ranked Croatian opponent did not go down without a fight in a 6-4, 7-6 (5) loss.