Andreescu was beaten 6-7, 6-4, 6-4 on home soil by Jabeur in a marathon match that lasted nearly four hours at IGA Stadium.

British number one Johanna Konta has pulled out of the Women's Tennis Association 1000 tournament with a knee injury, giving 15^th seed American Coco Gauff a walkover to the quarter-finals.

The withdrawal adds to a plagued summer for the 30-year-old Briton, who pulled out of Wimbledon when a member of her team tested positive for COVID-19 before she missed the Olympics after contracting the virus herself.

Italian Camila Giorgi will meet Gauff in the next round after she surprisingly beat Czech seventh seed Petra Kvitová in straight sets.

Top seed Aryna Sabalenka of Belarus breezed past Canadian Rebecca Marino 6-1, 6-3 to set up a quarter-final match-up with her compatriot Victoria Azarenka after the 32-year-old defeated Maria Sakkari of Greece following a third-set tie-break.

Danielle Collins was let down by her serve against Jessica Pegula in an all-American clash, losing 6-4, 3-6, 7-5.

This year's Wimbledon finalist Karolína Plíšková of the Czech Republic beat 19-year-old American Amanda Anisimova 6-1, 7-6, and is set to face Spaniard Sara Sorribes Tormo after she beat Plíšková's fellow Czech and Olympic gold medallist Kateřina Siniaková.

In the men's tournament, held in Toronto, world number two Daniil Medvedev of Russia hit 10 aces past Australia's James Duckworth in a 6-2, 6-4, victory.

He will face Wimbledon semi-finalist Hubert Hurkacz in the quarter-finals following the Polish number one's comeback , 6-7, 6-4, 6-4 triumph against Georgian Nikoloz Basilashvili.

American John Isner caused an upset as he beat fourth seed Russian Andrey Rublev 7-5, 7-6.

He is set to play Gaël Monfils after the Frenchman overcame Isner's countryman Frances Tiafoe 6-1, 7-6.

Reilly Opelka of the United States downed South African Lloyd Harris 4-6, 7-6, 7-6 in a thrilling contest.

Opelka will take on Roberto Bautista Agut following the Spaniard's 6-3, 3-6, 7-5, win over Argentine Diego Schwartzman.

There were no surprises in the remaining matches as Greece's Stefanos Tsitsipas and Norwegian Casper Ruud humbled their opponents, Karen Khachanov of Russia and Serb Dušan Lajović, respectively, in straight-set victories.