No. 4 Jessica Pegula of the United States had no trouble dispatching Italy's Jasmine Paolini 6-4, 6-0, on Thursday before rain halted play in Montreal.
Pegula, who advanced to the quarterfinals with the 69-minute victory, finished with six aces to one double fault. Pegula also broke Paolini five times on 11 chances.
Seeking her first National Bank Open title after consecutive semifinal appearances at the event, Pegula will play No. 6 Coco Gauff — Pegula's doubles partner - who cruised past No. 9 seed Marketa Vondrousova of the Czech Republic with a 6-3, 6-0 victory following a pair of lengthy rain delays.
World No. 1 Iga Swiatek of Poland survived the delays and beat Czech No. 14 seed Karolina Muchova 6-1, 4-6, 6-4 in a two-hour, 47-minute match to reach the quarterfinals.
"You have to find energy even though we've been here since 9 a.m.," Swiatek said. "For sure, it was a pretty extraordinary day, and I don't think I've had such a situation in my career so there is the opportunity to learn something new and see what I'm capable (of) — even though we played this match, like, three times."
On Friday, Swiatek will oppose American qualifier Danielle Collins, who swept Canadian Leylah Fernandez 6-2, 6-3. Collins won 70.3 percent of her first serve and saved 7 of 10 break points.
In other action Thursday, No. 10 Daria Kasatkina of Russia defeated Marie Bouzkova of the Czech Republic in straight sets 6-3, 6-4 after their match was also interrupted by rain.
No. 3 Elena Rybakina of Kazakhstan advanced to the quarterfinals with a 6-3, 6-3 victory over American Sloane Stephens. Rybakina will face Kasatkina on Friday.
Thursday night's late match between No. 2 Aryna Sabalenka of Belarus and No. 15 Liudmila Samsonova of Russia was moved to Friday.
Also on Friday, Swiss 12th seed Belinda Bencic will take on seventh-seeded Petra Kvitova of the Czech Republic.
—Field Level Media