No.1 seed Elina Svitolina of Ukraine continued an undefeated run in Chicago as she ousted Elena-Gabriela Ruse of Romania, 6-3, 6-3, to move into the Chicago Fall Tennis Classic quarterfinals.

Svitolina claimed her first title of the season at the Chicago Women's Open just prior to the US Open, and she has now won seven consecutive matches in the Windy City with her 1-hour and 48-minute victory over World No.98 Ruse.

"It was a good match today, and I think there were lots of tough games, tough rallies," Svitolina said, after her win. "In the end, the score was 6-3, 6-3, but it was quite a tough battle.

"It was up-and-down a little bit, but in the end, I think I was quite solid, and was really happy with my movement today. Happy I could win in two sets." 

Stat corner: Ruse, who won her first WTA singles title earlier this season on the clay courts of Hamburg, was playing a member of the Top 10 for the first time in her career. Her win over World No.37 Camila Giorgi in the first round this week was the best of her career by ranking to date.

But 6th-ranked Svitolina had the answers to quash the Romanian's run, winning 63 percent of Ruse's second-service points. Svitolina held a whopping 16 break points during the match, and though she only converted four of those, that was more than enough to ease to victory.

Svitolina currently owns the longest streak for most consecutive weeks in the Top 10, with the Chicago Fall Tennis Classic marking her 209th straight week within that echelon. This week's trip into the elite eight is also Svitolina's 10th quarterfinal of the season.

Key moments: An outrageous 17-minute game opened the clash, with nine deuces coming and going before Svitolina at last ended that battle by converting her fifth break point to grasp a 1-0 lead.

Ruse eventually clawed that break back, slamming a backhand crosscourt winner to level at 3-3, but Svitolina swept through the next game to reclaim her advantage, then broke once more for good measure to close out the first set.

Another lengthy game, with seven deuces, went Ruse’s way as she held for 1-1 in the second set, but it was Svitolina who notched the only service break in that set as she edged ahead 4-2.

Svitolina served for the match at 5-3, but big Ruse groundstrokes helped the Romanian fend off a match point and earn her second break point of that game. However, a passing winner gave Svitolina a second match point in that game, which she converted with her second ace of the day.

Next up: Svitolina will take on No.6 seed Ons Jabeur of Tunisia in the quarterfinals, after Jabeur had a comeback victory over No.9 seed Jessica Pegula of the United States earlier on Thursday. Svitolina has won all three of her prior professional meetings with Jabeur, but their history dates back to juniors.

"I think the first time I played against her [was] in 2010 in Belgium," Svitolina recalled about their junior days. "And then the next week we played in the final of Roland Garros! It was really special for both of us.

"She's such a nice person, and it's going to be a big battle, and I'll try to do my best."

Muguruza gets walkover past Azarenka: Meanwhile, No.2 seed Garbiñe Muguruza of Spain advanced to the quarterfinals without striking a ball, as No.14 seed Victoria Azarenka of Belarus withdrew from their round-of-16 encounter.

The pair of two-time Grand Slam champions and former World No.1 players had been slated to meet for the sixth time, with Muguruza holding a 3-2 lead in their head-to-head.

In the quarterfinals, Muguruza will now face this week's big surprise package: 22-year-old Japanese qualifier Mai Hontama, who stunned Shelby Rogers, 6-4, 6-7(1), 6-1.

Hontama, ranked World No.200, is contesting the first tour-level main draw of her career this week, but the occasion has not prevented her from notching big wins. In her first tour-level match in the opening round, she cruised past former World No.4 Caroline Garcia, 6-3, 6-0.

After receiving a second-round walkover from No.11 seed Anett Kontaveit, Hontama collected another Top 60 win over World No.41 Rogers, who had just eliminated Bianca Andreescu on Wednesday.

Hontama shook off a poor showing in the second-set tiebreak to sweep through the third set and claim the win after two-and-a-half hours of play.

Olympic medalists advance: Olympic medalists went 3-for-3 on Thursday in Chicago, as bronze medalist Svitolina was joined in the quarterfinals by the last two players left standing at Tokyo 2020.

Silver medalist Marketa Vondrousova of the Czech Republic claimed one remaining spot in the elite eight, after she beat No.16 seed Jil Teichmann, 6-4, 6-3, in an hour and 19 minutes. Vondrousova will face No.10 seed Danielle Collins in the quarters.

And gold medalist Belinda Bencic of Switzerland, the No.3 seed this week, staved off Tereza Martincova of the Czech Republic, 6-2, 7-6(5), in an hour and 41 minutes.

Bencic converted four of her eight break points in the match but was nearly forced into a third set. Serving at 5-6 in the second set, Bencic was down triple set point at 0-40 before steering herself out of that peril and winning the subsequent tiebreak.

Bencic advances to a quarterfinal showdown with No.5 seed Elena Rybakina, in a rematch of the Olympics semifinals. Rybakina finished fourth at the Olympics, meaning all four Olympic semifinalists moved into the Chicago quarterfinals on Thursday.