Top-seeded Italian Flavia Pennetta was upended by qualifier Betina Jozami 6-1 2-6 6-4 in the opening round of the Copa Colsanitas Santander on Tuesday.
Fresh from capturing her fifth career title in Vina del Mar on Sunday, Pennetta struggled and trailed Betina 1-6 6-2 4-5, when play was suspended.
Jozami then wrapped up the match in the first game when play resumed.
The loss was a bit of a shock for Pennetta, who won this tournament in 2005 and was the runner-up 2006. In winning at Vina del Mar, the 25-year-old won every set of her five matches and went from 33rd to 30th in the world with the win.
But now Pennetta will be heading home, along with fourth-seeded Frenchwoman Emilie Loit, who was ousted by Paraguay's Rossana De Los Rios 7-5 6-3.
Meanwhile, Jozami will face Mariya Koryttseva, who posted a 1-6 6-4 7-6 victory over Petra Cetkovska of Ukraine earlier in the day.
Third-seeded Pauline Parmentier of France advanced with a straight-sets win over Germany's Julia Schruff 6-4 6-3.
Parmentier will now face wildcard Catalina Castano of Colombia on Wednesday.
Yvonne Meusburger of Austria was another seeded player to advance after she cruised to a straight-sets win over American Jill Craybas 6-4 6-4. She will now face wildcard Mariana Duque Marino of Colombia.
Seventh-seeded Edina Gallovits of Romania advanced with a 6-1 6-2 win over India's Sunitha Rao, and will face sixth-seeded Italian Sara Errani.
Finally, ninth-seed German Martina Muller beat Viky Nunez Fuentes 7-5 7-6 (7-5) and will face Romanian Sorana Cirstea.
Results from the Copa Colsanitas Santander, Bogota
Betina Jozami (Argentina) bt 1-Flavia Pennetta (Italy) 6-1 2-6 6-4
3-Pauline Parmentier (France) bt Julia Schruff (Germany) 6-4 6-3
Rossana de los Rios (Paraguay) bt 4-Emilie Loit (France) 7-5 6-3
5-Yvonne Meusburger (Austria) bt Jill Craybas (USA) 6-4 6-4
7-Edina Gallovits (Romania) bt Sunitha Rao (India) 6-1 6-2
9-Martina Muller (Germany) bt Viky Nunez Fuentes (Colombia) 7-5 7-6 (7-5)
Mariya Koryttseva (Ukraine) bt Petra Cetkovska (Czech Republic) 6-1 4-6 7-6 (7-3)
Lourdes Dominguez Lino (Spain) bt Maria Irigoyen (Argentina) 6-4 6-0
Sorana Cirstea (Romania) bt Camille Pin (France) 2-6 6-2 6-4
Maria Elena Camerin (Italy) bt Maret Ani (Estonia) 4-6 6-3 6-2
Nuria Llagostera Vives (Spain) bt Tatjana Malek (Germany) 6-4 6-2
Carla Suarez Navarro (Spain) bt Bethanie Mattek (USA) 7-5 6-2
Catalina Castano (Colombia) bt Kaia Kanepi (Estonia) 6-3 7-5