Mariana Duque caused an upset at the Copa Claro Colsanitis with a straight-set victory over second seed Sloane Stephens.
Duque rattled off seven games on the bounce en route to a 6-3 6-3 victory over the American.
"I was prepared for a hard match," Duque told wtatennis.com. "You never know what the score is going to be, but the match was much tougher than what the score indicated.
"I'm so happy. Not just for beating Stephens but also because I played really well. I think from the start of the match, I was really confident and it showed during the match."
Fourth seed Anna Schmiedlova also crashed out, losing 6-3 6-1 to Irina Begu – however Paula Ormaechea and Caroline Garcia advanced.
Seventh seed Ormaechea, a runner-up in Bogota last year, beat Patricia Mayr-Achleitner 7-5 6-1, while No 5-ranked Garcia toppled Florencia Molinero 6-3 6-4.
Sofia Shapatava, Maria Irigoyen and Danka Kovinic all needed three sets to reach the second round, with respective wins over Dinah Pfizenmaier, Alla Kudryavtseva and Nicole Gibbs.
Yuliana Lizarazo registered a 7-5 6-4 win over Sachia Vickery, Romina Oprandi finished strongly to beat Tatjana Maria 7-6 (9-7) 6-1, while the 2012 champion Lara Arruabarrena powered to a 6-1 6-0 victory over Maria Herazo Gonzalez in 45 minutes.