No. 3 seed Stefanos Tsitsipas came back from a set down to win 4-6, 6-3, 6-2 against defending champion Nikoloz Basilashvili on Thursday to book himself a spot in the men's quarter-finals at the 2019 China Open.

The Greek youngster will face John Isner in the last eight after the American downed Great Britain's Dan Evans 7-6 (3), 7-5. Meanwhile, second seed Alexander Zverev is through to the last eight after dismantling Felix Auger-Aliassime in straight sets.

Zverev is set to face Sam Querrey in the last eight after the latter survived a three-set tilt against Diego Schwartzman. 

In the women's draw, No. 4 seed Naomi Osaka won her third-round match against America's Alison Riske 6-4, 6-0, and defending champion Caroline Wozniacki beat Katerina Siniakova 7-5, 6-4.

U.S. Open champion Bianca Andreescu and Daria Kasatkina have also advanced, with the former beating Jennifer Brady in straight sets. Kasatkina did the same to Ekaterina Alexandrova.

China Open, Thursday Results

Men's Draw 

John Isner bt. Dan Evans: 7-6 (3), 7-5

(3) Stefanos Tsitsipas bt. Nikoloz Basilashvili: 4-6, 6-3, 6-2

Sam Querrey bt. Diego Schwartzman: 7-6 (2), 6-7 (6), 6-3

(2) Alexander Zverev bt. Felix Auger-Aliassime: 6-3, 6-1

Women's Draw

(4) Naomi Osaka bt. Alison Riske: 6-4, 6-0

(16) Caroline Wozniacki bt. Katerina Siniakova: 7-5, 6-4

Daria Kasatkina bt. Ekaterina Alexandrova: 6-4, 6-3

(5) Bianca Andreescu bt. Jennifer Brady: 6-1, 6-3,

For the full results and draw, visit the competition website.

Tsitsipas went into the China Open in Beijing on a run of four successive tournaments in which he failed to get past the second round.

It looked as though that poor run could continue when he lost a tight opening set to world No. 17 Basilashvili.

The 21-year-old did not play poorly, serving at 72 per cent and earning six break-point opportunities.

The Georgian, though, saved all of them, and he crucially took one of his four on Tsitsipas' serve to edge into the lead.

The second set was similarly nip and tuck, but this time Basilashvili could only save five of the six break points on his serve, while he was unable to take the one opportunity he got when Tsitsipas had the ball in hand.

The world No. 7 eventually came through in two hours, eight minutes after finally gaining some breathing room in the decider with a double break.

His first-serve percentage in the third set was only 44, but he saved both break point opportunities Basilashvili earned and preyed effectively on his opponent's second serve:

Isner, meanwhile, needed 110 minutes to oust Evans in two sets.

The first was an exhibition in impressive serving from the duo as Isner hit 15 aces and Evans made 75 per cent of his first serves.

The inevitable tiebreak was taken by Isner, who then took the only break point of the second set to book his spot in the last eight:

Zverev stayed strong on serve to keep Auger-Aliassime at bay. The German smashed five aces and wasn't broken once.

By contrast, Auger-Aliassime lost four of seven break points, per the ATP official website. The difference in the service games had proved decisive for Zverev, who looks to be in the kind of form to go all the way.

In the women's draw, Osaka eventually thrashed Riske, not allowing her a single game in the second set after a tight first:

It sets up a quarter-final meeting between the Japanese star and Andreescu, who continued her remarkable winning streak with a 67-minute victory over Brady:

Osaka is also in fine form after her recent triumph at the Pan Pacific Open. That was her first title since she became a two-time Grand Slam champion at the 2019 Australian Open, and the 21-year-old is already aware of the challenge Andreescu will pose:

Wozniacki is still the player to beat, though, after 2018's winner showed resilience to overcome Siniakova. The first set lasted 45 minutes, but Wozniacki wore down Siniakova by attacking her forehand.

Kasatkina will have to be prepared for Wozniacki's aggressive style and desire to start fast.