Top seed Jannik Sinner moved into the semifinals of the China Open on Monday with a 6:2, 7:6 (6) win over Jiri Lehecka.

Just two days after the World Anti-Doping Agency announced it was seeking a one- to two-year ban for the US Open champion, who twice tested positive for an anabolic steroid in March, the 23-year-old appeared The Italian didn’t seem to be distracted as he quickly dealt with the 37th-ranked Lehecka’s serve in a dominant first set.

The defending champion was down two set points at 4-6 in the second-set tiebreak, but found a way to complete his 14th straight victory and advance to the semifinals against either fifth-seeded Andrey Rubev or local favorite No. 96 ranked Bu to draft Yunchaokete, who plays later on Monday.

“So happy with how I handled a difficult situation,” Sinner said. “I feel like I can still improve a few things here. Hopefully tomorrow will be the day I feel better on the pitch.”

Third-seeded Carlos Alcaraz reached the semifinals of the China Open for the second straight year after an impressive 7-5, 6-2 win over Karen Khachanov on Monday.

The 21-year-old Spaniard was typically relentless from the baseline, crushing 27th-seeded Khachanov’s serve games and converting four of 12 service break opportunities to win in 96 minutes.

“I always try to apply a little pressure when they’re pitching, just to tell them in a certain way that I’m going to be there,” Alcaraz said. “If they want to win the service game or beat me, they have to accept the fight and play really good tennis. For me, that’s what I’m constantly trying to show them.”

It was Alcaraz’s 46th win of the season and the victory enabled the reigning French Open and Wimbledon champion to climb back up to second place in the ATP Live Rankings over the absent Alexander Zverev.

Alcaraz will face Daniil Medvedev in the semifinals after the fifth-seeded Russian defeated Flavio Cobolli of Italy 6-2, 6-4.

Medvedev, still hoping for his first title of the year, made 16 fewer unforced errors than the Italian and converted four of his eight break point chances, completing a solid 88-minute win.

Earlier, Andrey Rublev defeated Alejandro Davidovich Fokina 6-4, 7-5 in a match that was broadcast from Sunday due to a rain delay.

No. 6-ranked Rublev had six aces and 21 winners, extending his career record to 5-0 against Davidovich Fokina.

The fifth-seeded Russian faced No. 96 local Bu Yunchaokete in the quarterfinals later on Monday.

Information from The Associated Press contributed to this report.