Aryna Sabalenka's shaky form continued at the Canadian Open against Ekaterina Alexandrova, who came through a topsy-turvy last-16 clash with a 7-6 (7-3) 4-6 6-4 win.

Sabalenka's wait for a first Canadian Open crown will go on for at least another year after the world number one was punished for a mistake-littered performance in Toronto.

Sabalenka actually took the first break of the contest just two games in, but Alexandrova applied relentless pressure to her serve from the off – missing a break point in the top seed's first service game then breaking in each of the next two.

Sabalenka got the set back on serve in game eight, although the players then traded two more breaks to force a tie-break – which Alexandrova sealed via a wayward forehand from her opponent.

The second set saw both players serve at a higher level, and the only break went Sabalenka's way shortly after she had fended off two chances for Alexandrova to go ahead.

But the momentum switched again in the deciding set, which was another chaotic affair featuring five breaks of serve. 

Alexandrova got three of those, converting her third match point to tee up a quarter-final clash with Elina Svitolina.

In her on-court interview, the 31-year-old said: "I just tried to play every single point as if it was the last one, because with her, you don't get a lot of chances during the match.

"I had a lot today, but I couldn't realise some of them. But honestly, I was trying not to think about the score or anything. Just hit the ball, and that's it.

"I'm super happy that I could win because after the second set, I thought the chance was already past me."

All smiles 

Ekaterina Alexandrova is into the quarterfinals!#NBO26 pic.twitter.com/5TUsFu53wa

— wta (@WTA) August 9, 2026

Svitolina booked her spot in the last eight with a 6-2 6-4 win over eighth seed Amanda Anisimova.

Svitolina had to hold off a late comeback attempt from Anisimova, who saved the first four match points she faced and threatened to get the second set back on serve from 5-1 down, but the Ukrainian got over the line at the fifth attempt with a powerful forehand to the baseline.

More three-set worries for Sabalenka

Alexandrova has now won 50% of her WTA Tour-level meetings with Sabalenka (5/10), and she is into her third quarter-final of the year after Abu Dhabi (where she was the runner-up) and Bad Homburg.

Saturday's win was also Alexandrova's third over a world number one at WTA-1000 events. Since the format was introduced in 2009, only Petra Kvitova, Elena Rybakina and Sabalenka (four each) have more, with each of those players reaching at least second in the rankings themselves (Alexandrova's highest ranking is 36th).

Sabalenka, meanwhile, has had her issues in matches that have gone the distance this year.

She is 4-6 in completed three-setters in 2026, and since the WTA Rankings were first published in 1975, only Caroline Wozniacki (seven, 2011) has ever suffered more such defeats in a single season as world number one.