ABU DHABI: Sofia Kenin opened her season Thursday by beating Yang Zhaoxuan 7-6 (4), 6-2 in the first round of the Abu Dhabi Open.

The American hit 11 aces against Yang to set up a second-round match against Kirsten Flipkens.

“Obviously a little bit of nerves. I had to try and find my groove,” said Kenin, the Australian Open champion who will try to defend her title next month. “First set was quite tough for me. I couldn’t find the ball, I guess. But second set I showed up strong and of course I feel like it’s because of the lack of matches for me.”

After a long pre-season, Kenin said she was happy to beat a player who had already had match practice in qualifying, but she had concerns about her own fatigue toward the end.

“I was like: ‘I just want to finish already. I’m too tired,’” Kenin said.

Also, fourth-seeded Aryna Sabalenka came back after trailing 5-3 in the opening set to beat Polona Hercog 7-6 (5), 6-2, sixth-seeded Elena Rybakina defeated Lucrezia Stefanini 6-1, 6-3, Hsieh Su-Wei upset eighth-seeded Marketa Vondrousova 3-6, 6-3, 7-6 (3), and Sara Sorribes Tormo beat French Open semifinalist Nadia Podoroska 6-3, 6-3.

Meanwhile, top 30 tennis pro Dayana Yastremska was provisionally suspended for failing an out-of-competition doping test, the International Tennis Federation announced Thursday.

Yastremska, a 20-year-old Ukrainian, tested positive for mesterolone metabolite, a prohibited substance that can be used to boost testosterone.

A punishment would not be decided until after a full hearing. The ITF said Yastremska has a right to appeal, but has not yet done so.

Yastremska reached a career-high ranking of No. 21 in January 2020, and her best showing at a Grand Slam tournament was reaching the fourth round at Wimbledon in her main-draw debut there in 2019.

She has won three WTA singles titles.

Yastremska provided a urine sample in November that was tested at the World Anti-Doping Agency laboratory in Montreal, the ITF said.