Star Metro - Zverev thrashes Shang to set up Djokovic quarter-final at China Open

The German top seed needed just 55 minutes to brush aside the Chinese wildcard, ranked 250th, firing nine aces along the way.

"Happy with the win," the world's second-ranked player said, adding that his 21-year-old opponent had been "dangerous" and had "nothing to lose".

"Looking forward to the next couple of weeks," he said ahead of his tie with Djokovic -- who has never lost a match in Beijing -- on Sunday.

Zverev's cruise into the next round comes as he trains his sights on the number-one spot currently held by Jannik Sinner.

The Italian won in Beijing last year but is not there this time around, and said on Saturday that he would not play at next week's Shanghai Masters either.

He did not give a reason for his latest withdrawal, but has not played since his Wimbledon title in July due to a right knee injury.

Also in the men's draw, third seed Daniil Medvedev eased into the quarter-finals with a 6-4, 6-3 win over Germany's Jan-Lennard Struff.

Alex de Minaur, seeded fifth, and Andrey Rublev both needed three sets to advance and will play each other in the last eight.

- 'Stop shouting' -

Earlier, Olympic champion Zheng Qinwen rebuked rowdy fans at her home tournament before opponent Anna Kalinskaya retired with injury to give the Chinese player a 6-7 (4/7), 6-4, 3-0 victory.

During a tight first-set tie-break, Zheng -- a beloved figure in her home country -- twice was heard telling spectators to "stop shouting" as she stepped up to serve.

"I thought the first set in particular was really difficult," Zheng told the crowd in an on-court interview after the two-hour-and-22-minute match.

"Indeed, seeing some movement in the audience, my emotions were not very stable," the 23-year-old added.

But she declared: "It's my problem, it's my problem," and vowed to adjust.

Chants for Zheng rang through the wind-rattled stadium before most points, with fans occasionally yelling at each other to quieten down.

The umpire also stepped in to warn people to stop moving around in the stands during play.

After levelling in the second set, the world number 54 was handed a lifeline when Russia's Kalinskaya retired three games down in the third due to injury.

Zheng next faces either Czech player Marie Bouzkova or Australia's Kimberly Birrell in the third round.

- Gauff digs deep -

In the women's draw, Coco Gauff kept her composure to beat Camila Osorio 7-6 (7/4), 4-6, 6-2, overcoming shaky serving to survive the second round.

The Colombian, ranked 66th, put up a formidable fight after double-faulting to lose a testy first-set tie-break, though she needed medicine to push through trouble with her back.

Osorio saved two match points but Gauff, the world number four, dug deep, rescuing long rallies with a solid backhand and cross-court saves.

"It was tough, it wasn't the cleanest," said the 22-year-old American after the two-hour-and-18-minute match.

"Just happy with how I was able to reset," she said.

She next faces Chinese teenager Sun Xinran, world number 582, who beat Spain's Cristina Bucsa 6-4, 7-5.

Sixth-seeded Elina Svitolina and former champion Iga Swiatek, seeded eighth, also went through on Saturday.

World number one Elena Rybakina is playing Armenia's 118th-ranked Alina Charaeva in the evening session.

A.Hill--SMC