Top seed Elina Svitolina squandered opportunities as she was shocked in the opening round of the Claro Open Colsanitas.
Ukrainian Svitolina wasted five match points before suffering a 7-5 1-6 7-6 (8-6) loss to the 2012 runner-up in Bogota Alexandra Panova on Wednesday.
The clash had been suspended late in the second set a day earlier, but world number 16 Svitolina would eventually bow out in the first round.
Svitolina led 6-3 in the tie-break before losing five straight points, going down in two hours, 45 minutes.
Her exit came a day after defending champion Teliana Pereira was eliminated.
Third seed Mariana Duque-Marino joined them, losing 3-6 7-6 (7-5) 6-4 to Amra Sadikovic.
Wednesday's only other first-round match involved Lourdes Dominguez Lino, a two-time champion of the WTA International event, as she overcame Patricia Maria Tig 5-7 6-4 6-4.
German sixth seed Tatjana Maria made a second-round exit, comfortably beaten 6-4 6-3 by Paula Cristina Goncalves.
Qualifier Catalina Pella, who beat Pereira, continued her run with a 6-3 6-2 win over Elitsa Kostova.
Lara Arruabarrena, the 2012 winner, was untroubled in a 6-1 6-0 thrashing of Anne Schaefer and Irina Falconi edged past Sherazad Reix 6-3 7-6 (7-2).