Fourth-seeded Jelena Ostapenko of Latvia delivered 28 winners while posting a 3-6, 7-6 (3), 6-2 victory over Spain's Paula Badosa in the second round of the National Bank Open in Toronto.

Ostapenko converted 5 of 6 break points while snapping Badosa's six-match winning streak. Badosa won last week's tour stop in Washington, D.C.

Ostapenko lost the opening set and later saw Badosa serve for the match in the second set. But Badosa committed two of her nine double faults during the game and Ostapenko remained alive and won the set in a tiebreaker.

In the third set, Ostapenko won 86.7 percent (13 of 15) of her first-serve points.

Ostapenko had nine aces but also committed nine double faults. Badosa had 24 winners and three double faults.

Ostapenko next faces Taylor Townsend, who rolled to a 6-0, 6-2 victory over Marina Stakusic of Canada.

Top-seeded Coco Gauff cruised to a 6-4, 6-4 victory over Wang Yafan of China.

Gauff had a 6-0 edge in aces, recorded 25 winners and saved 5 of 7 break points. But she was not pleased with the 36 unforced errors on her ledger.

"I think I made some more errors than I'm used to, but overall, I think I was building the points the correct way," Gauff said. "I think I just have to do better making those next two balls. But overall, I'm happy with I played."

Gauff next faces No. 14 seed Diana Shnaider, who outlasted Poland's Magdalena Frech 2-6, 6-3, 7-6 (5).

Second-seeded Aryna Sabalenka of Belarus rolled to a 6-2, 6-2 victory over China's Yuan Yue, while Amanda Anisimova pulled off a 6-4, 6-3 upset of fifth-seeded Russian Daria Kasatkina.

Sixth-seeded Russian Liudmila Samsonova registered a 6-4, 6-2 win over Japan's Moyuka Uchijima.

Peyton Stearns advanced when Madison Keys withdrew in the third set with a thigh injury. Sterns led 3-6, 7-5, 3-0.

No. 8 Emma Navarro defeated Poland's Magda Linette 6-2, 6-4; No. 10 Anna Kalinskaya of Russia beat Ukraine's Lesia Tsurenko 6-2, 6-2, and No. 11 Marta Kostyuk defeated Elina Svitolina 6-2, 2-6, 6-2 in an all-Ukraine matchup.

Katie Boulter of Great Britain advanced when No. 13 seed Beatriz Haddad Maia of Brazil withdrew due to a lower back injury. The score was tied 1-1 in the opening set.

Ashlyn Krueger stopped No. 15 Leylah Fernandez of Canada 6-4, 6-2.

Belarus' Victoria Azarenka, the 12th seed, rallied for a 3-6, 7-5, 6-1 win over Belgium's Greet Minnen.

Four-time major champion Naomi Osaka of Japan fell 6-3, 6-4 to Belgium's Elise Mertens. Osaka has reached the quarterfinals in just two of her 15 events this year, and she has yet to make a semifinal appearance.

--Field Level Media