Bucharest - Polona Hercog of Slovenia took advantage of a poor performance from fifth-seeded Monica Niculescu of Romania to win their Bucharest Open second-round match 6-4, 6-3 on Wednesday.
"I made a lot of mistakes and I relied a lot on my return which was not good today," said Niculescu, who beat Hercog in the 2014 quarterfinals.
Hercog plays fourth-seeded Laura Siegemund in the quarterfinals after the German beat Japanese qualifier Misa Eguchi 6-4, 6-1.
Vania King of the United States ousted eighth-seeded Cagla Buyukakcay of Turkey 7-6 (5), 4-6, 6-1 to set up a match against Pauline Parmentier. The Frenchwoman defeated Aliaksandra Sasnovich of Belarus 7-6 (3), 6-4.