British number one Johanna Konta was beaten 6-3 6-4 by defending champion Elina Svitolina in her second match of the day at the Rogers Cup in Montreal.
Ukraine’s Svitolina, the world number five, took 85 minutes to move into the quarter-finals.
Konta, 27, had earlier beaten two-time champion Victoria Azarenka in a match that was halted by rain on Wednesday.
The world number 43 led 6-3 3-0 overnight and completed a comfortable 6-3 6-1 victory on Thursday.
Svitolina had reached the third round when her Romanian opponent Mihaela Buzarnescu retired from their match on Tuesday with the score 6-3 6-7 (5-7) 4-3.
Elsewhere, Romania’s world number one Simona Halep beat seven-time Grand Slam champion Venus Williams 6-2 6-2, after the American had earlier beaten Romanian Sorana Cirstea 7-6 (7-4) 6-4.
Earlier Halep had survived a three-hour, seven-minute encounter with Russia’s world number 29 Anastasia Pavlyuchenkova in her delayed second-round match, winning 7-6 (11-9) 4-6 7-5.
Halep’s quarter-final opponent is Caroline Garcia, after the Frenchwoman beat Maria Sharapova 6-3 6-2.
Danish second seed Caroline Wozniacki was beaten 7-5 2-6 7-6 by Aryna Sabalenka of Belarus in her second-round match. Sabalenka then lost 6-2 7-6 6-0 to Elise Mertens.
American world number three Sloane Stephens is already in the quarter-finals after beating Spanish qualifier Carla Suarez Navarro 6-2 7-5. She will face Latvia’s Anastasija Sevastova, who beat Julia Goerges of Germany 6-3 7-6 (7-2).
And Australian 22-year-old Ashleigh Barty joined her in the last eight with a 7-6 (7-3) 6-4 victory over Alize Cornet of France.
She next faces Holland’s Kiki Bertens, who beat eighth seed Petra Kvitova 6-3 6-2.
|Simona Halep v Caroline Garcia||Anastasija Sevastova v Sloane Stephens|
|Ashleigh Barty v Kiki Bertens||Elina Svitolina v Elise Mertens|