Aryna Sabalenka and Kaja Juvan came into Wednesday's second-round match at the Adelaide International 1 about as far apart as two players can be in the WTA Top 100, but a difference of 98 places in the rankings proved no obstacle for the Slovenian, who won 7-6(6), 6-1. 

Juvan's previous best win by ranking was a 6-3, 6-3 win over then-World No.11 Belinda Bencic in the first round of Wimbledon last summer, one of three previous wins she had against Top 20 players. 

Hard court heroics: Juvan, 21 and the World No. 100, was previously 0-2 in her career against the Top 10, but neither match was played on a hard court. In 2019, she took a set from then-World No. 10 Serena Williams in their second-round meeting at Wimbledon and she was beaten by Iga Swiatek in the first round of the French Open last year. 

"I was a little bit scared at first because she's incredible and she has done so many things really, really well. But on the other hand, it's the start of the season, it depends on the day a little bit, and I really believed that I could do it."

- Kaja Juvan

Serve struggles sink Sabalenka: Twice a break ahead in the first set, Sabalenka was never able to stretch her lead — and the World No. 2's inability to settle in on serve was a theme of the match.

After trailing 2-0 and 6-5 in the opener, Juvan saved set point at 6-5 in the tiebreak — after losing her own 5-3 lead — and won the last three points.

Sabalenka served four of seven first-set double faults in the tiebreak, and those woes continued into the second set. In four service games she landed just 33% of her first serves and put just one second serve in play, racking up 11 more double faults for 18 total in the 89-minute match.

Her opponent empathized.

"I really enjoyed the first set," Juvan said. "I love when matches get tight, when it's competitive and when it's a really tight fight. I was feeling a little bit sorry at some points because I ... knew she's not doing the best with the serve and we all know how that feels at one point.

"I know she can do it better, but on the other hand, I was just saying to myself, 'Focus. Stay here until the end. It can turn at any point.' I was really just trying to stay there until the very end and really fight."

To her credit, Juvan didn't hit a double fault herself, and also served four aces.

Up next for Juvan: The first player through to the quarterfinals, Juvan will next face either Anastasia Gasanova — who upset No.8 seed Elina Svitolina in the first round — or Misaki Doi with an unseeded semifinalist guaranteed. 

Rogers upsets Sakkari, sets quarterfinal vs. Rybakina

After Juvan picked up her first career Top 10 win, Shelby Rogers followed with her fourth, a 7-6(5), 2-6, 6-4 win over No.3 seed and World No. 6 Maria Sakkari. 

Rogers defeated Sakkari in straight sets at Wimbledon last July, and at 7-6(5), 2-0 ahead, looked on course for another; however, the American lost the next seven games before resetting for a 2 hour, 18-minute win. 

Words from the winner: "It's nice to start with a big win like that. I knew it was going to be really tough today. She's coming off an incredible season last year and she's such a great competitor, so I knew I had to bring my best tennis, whatever that looks like at the beginning of the year."

Rogers, who revealed in her on-court interview that her 2022 goal is to win her first tour-level title, will look for a second win against a seeded player in the quarterfinals when she faces No.7 seed Elena Rybakina. The pair have played three times in the last 18 months, with Rybakina holding a 2-1 head-to-head lead.

Jimmie48/WTA

While Rogers was working on her upset, Rybakina earned a straightforward 6-3, 6-4 win over Czech qualifier Marie Bouzkova to book her own spot in the last eight.