Alcaraz sealed a place in the men's quarter-finals with a smooth 6-2, 6-2 victory over Italy's Lorenzo Musetti in Beijing.

The world number two overpowered his opponent and seized the first set when Musetti whacked a baseline backhand into the net.

The Spaniard then broke serve twice in the second set and saw out a comfortable match with an unreturned serve.

He will next face Casper Ruud after the world number nine came back to beat Argentina's Tomas Etcheverry 1-6, 7-5, 7-6 (9-7).

"I feel great, honestly. It was a good performance against a really tough opponent," Alcaraz said at a post-match news briefing.

"(My level) didn't (go) up and down. I stayed at a high level, high quality, during the whole match," the 20-year-old said.

The match balls have been a sticking point in the tournament's early rounds, with Alcaraz's main challenger Daniil Medvedev describing them on Saturday as "like a grapefruit".

Alcaraz said Sunday he had also felt the distinct quality of the balls, which Medvedev said were also quick to fluff up, "since day one".

"It's something tough, but tennis players have to get used to the balls in every tournament," he said in response to a question from AFP.

"Here, in just one or two games, the balls become really different from (when they're) new. It's a kind of different (style of) play," he said.

Also on Sunday, world number seven Jannik Sinner obliterated Japan's Yoshihito Nishioka 6-2, 6-0.

The Italian will play a quarter-final against Bulgaria's Grigor Dimitrov after he upset fourth-ranked Holger Rune 6-3, 7-5.

World number one Aryna Sabalenka earlier sailed into the second round of the women's draw with an imperious 6-1, 6-2 defeat of American Sofia Kenin.

The Belarusian pummelled Kenin with a succession of mighty serves and groundstrokes and wrapped up the opening set with an ace after just 23 minutes.

The 25-year-old broke serve twice more in the second set as Kenin -- playing with heavy strapping on her left thigh -- failed to muster a response.

Sabalenka sealed the match with yet another unreturned serve to set up a tie against Britain's Katie Boulter, ranked number 54 in the world.

"Honestly, I didn't expect to play that good on my serve -- in practice, it didn't work very well," Sabalenka said at a post-match briefing.

"But I was super hyped that I was able to bring that level on my serve today. I think it helped a lot," she said.

"I think that was the key of today's match."

The China Open is taking place for the first time since 2019 after Beijing ended its isolationist zero-Covid policies.

All of the eight top-ranked men are taking part except 24-time Grand Slam winner Novak Djokovic, while all of the women's top eight are in action.

The women's tournament is also the first since its global governing body ended a boycott of China this year.

The embargo had been declared after Chinese player Peng Shuai made sexual assault accusations against a top government official.

© 2023 AFP