Anastasija Sevastova stunned two-time defending champion Jessica Pegula 3-6, 6-4, 6-1 on Friday to book a fourth-round clash with Naomi Osaka at the WTA Canadian Open.
Sevastova, a former world No 11 now ranked 386th, snapped fourth-ranked Pegula's 11-match WTA Canada win streak, the longest since Serena Williams reeled off 14 consecutive wins in 2011, 2013 and 2014.
‼️Down goes the Defending Champion‼️
— wta (@WTA) August 1, 2025
Anastasija Sevastova upsets Pegula 3-6, 6-4, 6-1.#OBN25 pic.twitter.com/IX7QYAUEUj
She will try to extend her Montreal run in a round of 16 meeting with Osaka, a four-time Grand Slam champion from Japan who ousted another Latvian, 22nd seed Jelena Ostapenko, 6-2, 6-4.
"Somehow, I was down 2-0 in the second set and started to play better and better," Sevastova said. "Third set I played really good.
"Just trying to stay on the court as long as possible," added Sevastova, who has dealt with injury since returning from maternity leave in February 2024.
In the night session, second-seeded Iga Swiatek – playing her first tournament since winning Wimbledon – raced into the fourth round with a 6-2, 6-2 victory over Germany's Eva Lys.
Swiatek next faces Denmark's Clara Tauson, who beat Yuliia Starodubtseva 6-3, 6-0.
Pegula, last year's US Open runner-up in her best Slam showing, was the first woman to win back to back Canadian Open titles since Martina Hingis in 1999-2000.
But she has struggled in recent months, dropping her openers at Wimbledon and at Washington last week.
The American broke to open the match and again at love to claim the first set.
But she couldn't maintain an early break in the second, with Sevastova breaking for a 5-4 lead and denying Pegula on three break chances before holding in the final game to force a third set in which she seized a 4-1 lead on the way to victory.
'WEIRD MATCH'
"It was a weird match for me," Pegula said. "I felt like I had total control and then I just played a couple of terrible games for, like, three games.
"That totally flipped the momentum of the match, and I went from being up a set and 2-0 to being down very quickly.
"I don't really feel like I'm playing great tennis," Pegula admitted. "At times I am, but I feel very up and down, kind of sloppy, which I don't like. I've got to figure it out."
Osaka, twice a winner at both the US and Australian Opens, is one match away from her first quarterfinal run at either a Grand Slam or WTA 1000 event since she returned from maternity leave at the start of 2024.
Now ranked 49th, Osaka broke on a double fault to capture the first set in 30 minutes and raced to a 3-1 lead in the second.
They exchanged breaks before Osaka served for the match with a 5-3 lead, but Ostapenko saved a match point on a forehand crosscourt winner and broke when Osaka sent a forehand beyond the baseline.
The Japanese star responded by breaking Ostapenko at love in the final game.
"I went in there knowing she's a great player and if I give her a chance she's going to hit a winner on me, so I just tried to keep my pace and stay as solid as I could," Osaka said.
Australian Open champion Madison Keys, seeded sixth, beat fellow American Caty McNally 2-6, 6-3, 6-3 and will next meet Karolina Muchova, a 6-7 (2/7), 6-2, 6-3 winner over Belinda Bencic.
Back in Business 👊
— wta (@WTA) August 1, 2025
Madison Keys forces the decider against McNally in Montreal.#OBN25 pic.twitter.com/lbutLDgj3j
Fifth-seeded American Amanda Anisimova, regrouping this week after a crushing 6-0, 6-0 loss to Swiatek in the Wimbledon final, swept past Britain's Emma Raducanu 6-2, 6-1.
She lined up a meeting with Ukrainian Elina Svitolina, who beat Russian Anna Kalinskaya 6-1, 6-1.