Shahar Peer came from a set down to claim a 2-6 7-5 6-3 win over Chanelle Scheepers and book her place in the quarter-finals of the Baku Cup.
The Israeli lost a one-sided first set and went a break down in the second before rallying to defeat her South African opponent.
The victory set up a last-eight meeting with Slovenia's Tadeja Majeric, who defeated Czech qualifier Tereza Martincova 7-6 (7-5) 6-3.
Seventh seed Elina Svitolina of Ukraine was also a second-round winner at the hard-court event, defeating Italy's Nastassja Burnett 6-0 7-6 (7-3) to set up a meeting with second seed Donna Vekic.
There were also wins for Galina Voskoboeva and Magda Linette, who will face Alexandra Cadantu and Ons Jabeur respectively in the quarter-finals.