Pattaya City, Thailand (SportsNetwork.com) - Top seeds Sabine Lisicki and Svetlana Kuznetsova both withdrew ahead of their scheduled second-round matches at the Pattaya Open.
The top-seeded Lisicki pulled out of the tournament with a right shoulder injury, while the second-seeded Kuznetsova bowed out with a muscle strain.
Andrea Hlavackova of the Czech Republic advanced to the quarterfinals at the top of the draw because of Lisicki's decision, while Germany's Julia Goerges was the beneficiary of Kuznetsova's withdrawal at the bottom.
Second-round winners Wednesday were third-seeded Sorana Cirstea of Romania, fourth-seeded Ekaterina Makarova of Russia and unseeded Czech Karolina Pliskova.
Cirstea cruised past American Alison Riske, 6-3, 6-4, and will next face Pliskova, who rallied for a 4-6, 6-3, 6-4 win over Russian qualifier Alla Kudryavtseva.
Makarova disposed of fellow Russian Vera Zvonareva in a 6-0, 6-2 rout.
Zvonareva, a wild card entry who won this title in 2009 and 2010, missed all of the 2013 season because of illness and a right shoulder injury. She returned to action earlier this year with a first-round loss to eventual champion Li Na in Shenzhen and also suffered a first-round setback to Casey Dellacqua at the Australian Open.
Next up for Makarova will be the winner of Thursday's second-round matchup between Japanese veteran Kimiko Date-Krumm and Slovenia's Tadeja Majeric.
The other two second-round matches on Thursday's schedule include fifth-seeded Elena Vesnina of Russia against Thai wild card Nicha Lertpitaksinchai and eighth-seeded Peng Shuai of China against Romanian qualifier Alexandra Dulgheru.
This week's champion will collect $43,000.