Jankovic breezed by Alexandra Cadantu 6-2, 6-1, improving her match record in 2013 to 4-3.
She will take on Karin Knapp in the semifinals after Knapp defeated Lara Arrubarrena-Vecino 6-3, 6-3.
The other semifinal will send Paula Ormaechea against qualifier Teliana Pereira. Ormaechea defeated Maria-Teresa Torro-Flor 6-1, 7-5, and Pereira ousted Mandy Minella 6-1, 6-2.
Pereira pulled off the tournament's biggest upset when she defeated No. 2 seed Alize Cornet in the second round.
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