The Spaniard's 3-6, 6-3, 6-0 win means she will climb to No 6 in the WTA rankings
The Tunisian stands on the verge of making yet more history for her country, while a place at the season-ending WTA finals is also within both players' grasp
Ons Jabeur scored her first win in four career meetings over top seed Elina Svitolina to set up a semi-final clash against Elena Rybakina
Svitolina remains undefeated in Chicago this year as she reaches the quarter-finals for the 10th time on tour this year
The 2019 US Open champion has now won only five matches in her past eight events on the tour