BOGOTÁ, Colombia - On Tuesday, Karin Knapp caused the latest shock at the XX Copa BBVA Colsanitas when she defeated No.2 seed Alexandra Dulgheru.

After the opening day exits of last year's runner-up Mathilde Johansson and Patricia Mayr-Achleitner, Dulgheru is the third seed to lose in the first round. However, while Johansson and Mayr-Achleitner came up short in grueling three set battles, Dulgheru's defeat was a far more one-sided affair.

Although Dulgheru arrived in Bogotá fresh from winning the ITF clay court event in nearby Cali last week, she looked all at sea at the Centro de Alto Rendimiento, throwing in 14 double faults in a 62 62 defeat. Knapp, who was once as high as No.35 in the world before a serious knee injury saw her career stall, will now face Colombian wildcard Catalina Castaño.

Another player struggling to find her feet on the Bogotá clay was No.5 seed and 2009 runner-up Gisela Dulko. However, after dropping an error-strewn opening set in just 22 minutes, the Argentine rallied to see off Kathrin Woerle, 16 62 64.

"No doubt I didn't start well," Dulko said. "I don't know if I was nervous, but I wasn't feeling the ball well and was rushing a little bit, as though I was looking for winners too quickly. My shots were also flying and I had a lot of unforced errors.

"The points were going by really quickly but in the second set I calmed down and started keeping the ball in play longer, and I found my rhythm again. I had a little trouble closing it out in the third set but I finished well, so in the end I was happy."

Reigning Bogotá champion Lourdes Domínguez Lino, meanwhile, had few problems in her opener, defeating Sharon Fichman, 62 62. Similarly untroubled was fellow seed Romina Oprandi, who advanced with another 62 62 win over Alexandra Cadantu.

Hoping to join Domínguez Lino and Oprandi in the round of 16 on Tuesday is top seed Marina Erakovic, who saw rain suspend her match against Stefanie Vogele after just one game. No.4 seed Jelena Dokic's meeting with Paula Ormaechea was also interrupted, with the Australian trailing 4-1 in the second set after taking the first 64.