World number two Rybakina from Kazakhstan defeated American 28th seed Ann Li 6-2, 7-5 in 90 minutes, winning five of six break chances while saving two of four against her.
Rybakina, who also won the 2022 Wimbledon title, advanced to a last-16 meeting with the winner of a later match between Russia’s Liudmila Samsonova and Australian Maya Joint.
Samsonova leads the career rivalry with Rybakina 4-2, but Rybakina has won their past two WTA meetings, most recently in last year’s Strasbourg final.
Fernandez, the 30th seed, dispatched 19-year-old Russian fifth seed Andreeva 6-1, 6-4 in 80 minutes, snapping a seven-match losing streak against top-10 opponents.
The last time she beat someone ranked so high was when she downed fourth-rated Jessica Pegula on her way to last year’s WTA Washington title.
“The key for me was to stay positive, stay strong, and to keep being patient,” Fernandez said. “She wasn’t going to give away some easy balls.
“In the beginning there were a lot of long rallies and that was a key for me to stick with it, trusting in my abilities, and to continue on playing my game throughout the match.”
Fernandez won 24 of 27 points on her first serve and captured 17 of 23 points on Andreeva’s second serves to advance. Andreeva made 34 unforced errors to 17 winners.
“I’ve trained a lot growing up in being consistent and hitting like 100 balls in a row,” Fernandez said. “That’s where I come back to. I know I can do it.
“I’ve put in the work. I know physically I’m strong. I know I can endure long rallies, long matches. So if it’s going to take 100 balls to hit to put it in to break her down, then so be it.”
The Canadian will next face the winner of a later match between four-time Grand Slam winner Naomi Osaka, the 11th seed from Japan who defeated Belgium’s 20th-seeded Elise Mertens 6-1, 6-2 in 71 minutes.
Osaka fired seven aces and took four of eight break points while denying Mertens on her three break chances.
Fernandez and Osaka have split two career meetings, the Canadian winning at the 2021 US Open on the way to a runner-up finish. Osaka won last year at Wuhan.
US fourth seed Coco Gauff, a two-time Grand Slam winner, advanced by defeating Greece’s Maria Sakkari 6-1, 6-4 in 76 minutes.
Gauff cruised to a 5-1 lead in the second set before Sakkari rallied within two points of pulling level before winning five of the last six points, taking the match on a backhand volley winner and service winner.
Gauff will next face 19-year-old Russian Alina Korneeva, who ousted US 13th seed Iva Jovic 6-3, 6-4. Korneeva won seven of eight break points to reach the last 16 after 82 minutes.
