BEIJING — Top-ranked Jannik Sinner rallied to beat Roman Safiullin 3-6, 6-2, 6-3 in the second round of the China Open on Saturday and learned afterward that his steroid case is far from over.

While Sinner was on court in Beijing, the World Anti-Doping Agency announced it was seeking a ban of one to two years for the US Open champion who tested positive twice for an anabolic steroid in March but was not suspended in a decision by an independent tribunal announced by the International Tennis Integrity Agency on Aug. 20 because the ITIA determined he was not to blame.

Sinner’s fate will now be determined by the Switzerland-based Court of Arbitration for Sport after WADA said it filed an appeal on Thursday.

“Obviously, I’m very disappointed and also surprised of this appeal, to be honest, because we had three hearings,” Sinner said at a press conference after his match Saturday. “All three hearings came out very positively for me.

“You know, I was not expecting it. I knew it couple of days ago, that they were going to appeal, that today it’s going to go official. But yeah, it’s surprise.”

On court Saturday, the two-time Grand Slam champion again found himself behind in the Chinese capital after Safiullin broke serve twice to claim the opening set.

Sinner’s power and laser-like accuracy from the baseline gradually chipped away at his Russian opponent and helped the Italian to win seven straight games from 2-2 in the second set to take the ascendancy and close out a gritty win.

Sinner, who has reached at least the quarterfinals at every tour-level event he has played in 2024, will next play Jiri Lehecka, who earlier defeated Roberto Bautista Agut 3-6, 6-2, 6-1.

Also Saturday, Italy’s Flavio Cabolli advanced after a 6-4, 6-2 win over Pavel Kotov.

Third-seeded Daniil Medvedev played his second-round match against French veteran Adrian Mannarino later Saturday.

In the women’s draw, US Open champion Aryna Sabalenka advanced to the third round with a 6-4, 6-1 win over Thai qualifier Mananchaya Sawangkaew.

“In the first set, I was struggling a little bit with the rhythm,” said Sabalenka, who’s best run in Beijing has only been to the quarterfinals. “In the second set, seems like everything started working much better. I think that’s why it was more smooth and better quality.”

The second-ranked Sabalenka is the top seed in Beijing in the absence of Iga Swiatek.

Next up for the three-time major winner is American Ashlyn Krueger, who beat New Zealand’s Lulu Sun 6-1, 7-6 (4).

Third-seeded Jasmine Paolini of Italy rallied from a poor first set to beat Denmark’s Clara Tauson 1-6, 7-5, 6-4. Paolini will play Poland’s Magda Linette after the 31st-seeded player also needed three sets to progress past Moyuka Uchijima 6-4, 4-6, 6-3.

Ninth-seeded Daria Kasatkina of Russia beat Croatian Jana Fett 6-1, 6-2. She will play Amanda Anisimova, who beat Camila Osorio of Colombia 1-6, 6-3, 6-4.

Wimbledon champion Barbora Krejcikova was upset 1-6, 6-4, 7-5 by Romania’s Jaqueline Cristian.

Japan Open

Tomas Machac upset fifth-seeded Tommy Paul 2-6, 6-3, 7-6 (4) to advance to the quarterfinals and continued a disappointing week for the top-seeded players in Tokyo.

Top-seeded Taylor Fritz, third-seeded Casper Ruud and fourth-seeded Stefaos Tsitsipas were all beaten in the first round, before second-seeded Hubert Hurkacz was also eliminated as he lost to US Open semifinalist Jack Draper 6-4, 6-4 in the second round.

Sixth-seeded Holger Rune is the highest-ranked seed remaining in the draw. Rune, from Denmark, beat home favorite Yoshihito Nishioka 6-2, 6-4.

Defending champion Ben Shelton, the No. 8 seed, is the only other seeded player left in the quarterfinal draw.

Alex Michelsen of the U.S. also advanced after a 6-1, 6-4 win over Australian Christopher O’Connell to set up a quarterfinal match against Machac.

Kei Nishikori beat Jordan Thompson 6-2, 6-3 and will play Rune in the quarterfinals.