BEIJING, Oct 6, 2023 (BSS/AFP) - Aryna Sabalenka said she channelled her frustration into ensuring she reached the China Open quarter-finals, after the world number one progressed despite an error-strewn second set against unseeded Jasmine Paolini in Beijing on Thursday.

Sabalenka eventually beat the Italian 6-4, 7-6 (7/4) to set up a tie with fifth-ranked Elena Rybakina in the next round on Friday.

Neither player gave much away in the opening set but Sabalenka proved her mettle when she struck three back-to-back aces for 5-4 before Paolini double-faulted on the crucial point in the following game.

The second set was a different story entirely, with the Belarusian storming into a 3-1 lead before losing consecutive service games to put Paolini, ranked 36th, in the driving seat.

But Sabalenka fought her way back from the brink, breaking serve for 5-5 and again for 6-6 before sealing the tie-break victory with a deft forehand down the line.

"There's a line that I shouldn't cross when I'm getting angry... Today I was just trying to stay under the line and control my aggression," Sabalenka told AFP after the match.

"In some moments of the match, it actually helped me to give myself some energy to fight, to move better, to play better," the 25-year-old said.

"Until 6-4, 3-1 I was serving amazingly, and then something happened -- probably because the balls got bigger and heavier, and I didn't adjust," she added.

"Then I started missing my serves and gave her a chance to come back into the match."

- Gauff glides through -

Earlier, US Open champion Coco Gauff shook off an indifferent first-set performance to glide into the quarter-finals with victory over Russia's Veronika Kudermetova.

The world number three triumphed 7-6 (7/5), 6-2 to set up a tie with Greece's Maria Sakkari, who beat homegrown talent Wang Xinyu 6-4, 2-6, 6-3.

Gauff roared into a 3-0 lead in the first set but was pegged back by an aggressive Kudermetova and had to save four set points to stay in it.

But she forced a tie-break and stole the set when the world number 16 double-faulted -- producing a howl of frustration -- before planting a forehand wide.

Set two was a much more comfortable affair for Gauff with the 19-year-old quickly notching a double-break and wrapping up the win when Kudermetova shovelled a forehand long.

"I was really just trying to push through, and honestly at (4-5), 0-40 I don't even know what happened," Gauff said when asked about her first-set comeback.

"I think obviously winning that first set... she probably was a little bit frustrated so she gave me a little bit more errors," she added.

"I don't really think I changed much in the second. I think I was just trying to continue to be aggressive."

World number 10 Caroline Garcia eased into the quarter-finals with a 6-3, 6-2 defeat of Ukraine's Anhelina Kalinina.

Garcia will play second-ranked Iga Swiatek in the next round after the Pole swatted aside compatriot Magda Linette on Wednesday.

The China Open is taking place for the first time since 2019 after Beijing did away with its long-standing zero-Covid policy.

The men's draw culminated on Wednesday when Italy's Jannik Sinner downed world number three Daniil Medvedev to take the trophy.