The last two seeded players were knocked out of the Copa BBVA Colsanitas in second-round matches Thursday in the clay-court tournament.
Top-seeded Marina Erakovic of New Zealand was beaten 6-4, 6-4 by Edina Gallovits-Hall of Romania while No. 5 Gisela Dulko lost to Alexandra Panova of Russia 7-5, 6-2.
In two other second-round matches, Karin Knapp of Italy defeated Catalina Castano of Colombia 6-3, 2-6, 6-2, and Paula Ormaechea of Argentina won against Petra Rampre of Slovenia 6-4, 3-6, 7-6 (4).
All eight players in the quarterfinals are ranked outside the WTA's top 100.
Second-seeded Alexandra Dulgheru of Romania was knocked out of the first round of the Copa BBVA Colsanitas on Tuesday, losing 6-2, 6-2 to Karin Knapp of Italy.
Three other seeded players made better starts at the clay-court tournament.
Gisela Dulko of Argentina, seeded No. 5, won 1-6, 6-2, 6-4 over Kathrin Woerle of Germany, No. 3 Romina Oprandi of Switzerland defeated Alexandra...
Results Tuesday from the Copa BBVA Colsanitas, a $220,00 WTA event on outdoor clay courts at the Centro de Alto Rendimiento Deportivo (seedings in parentheses):
Singles First Round Karin Knapp, Italy, def. Alexandra Dulgheru (2), Romania, 6-2, 6-2.
Gisela Dulko (5), Argentina, def. Kathrin Woerle, Germany, 1-6, 6-2, 6-4.
Romina Oprandi (3), Switzerland, def. Alexandra Cadantu...