After hitting 18 double faults, Aryna Sabalenka loses season opener to Kaja Juvan in Adelaide

ADELAIDE, Australia (AP) — Second-ranked Aryna Sabalenka had an upset 7-6 (6), 6-1 loss to No. 100-ranked Kaja Juvan on Wednesday in her first match of the season at the Adelaide International, one of the main tune-up tournaments for the Australian Open.

Sabalenka, a semifinalist at Wimbledon and the US Open last year, wasted a set point as she struggled with her serve in the tiebreaker. She then had 11 double-faults in the second set to give her 18 in total for the match.

The win was Juvan's first against a Top 10 player and earned her a spot in the quarterfinals.

"I was a little bit scared at first because she's incredible and she has done so many things really, really well," Juvan said. "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."

Sabalenka and top-ranked Ash Barty had first-round byes in Adelaide. Barty was scheduled to play American teenager Coco Gauff later Wednesday.

Travel restrictions during the COVID-19 pandemic mean there's a crammed schedule of tournaments in Australia before the year's first major starts Jan. 17 at Melbourne Park.

The WTA 500 event in Adelaide is one of three women's tournaments this week, including two in the so-called Summer Set in Melbourne.

The main men's event this week is the 16-team ATP Cup in Sydney, with Daniil Medvedev aiming to help Russia defend its title. Rafael Nadal is playing in a tune-up tournament in Melbourne.

After months of uncertainty, No. 1-ranked Novak Djokovic confirmed overnight he'd received a medical exemption from Australia's strict COVID-19 vaccine requirements and he was heading to Melbourne in a bid to defend his Australian Open title.

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