ATP Tour news: Jannik Sinner stuns Stefanos Tsitsipas to reach Rotterdam quarter-finals

The Italian lost to Tsitsipas over five sets at the Australian Open in one of the best matches of the tournament - the Greek going on to reach the final - but recorded a 6-4 6-3 victory on Thursday for the first top-three win of his career.

"It means a lot, obviously," Sinner said on atptour.com. "I'm very happy. I played some good tennis, very focused today. Hopefully I can keep it going but, for sure, Stef is an incredible player. I have a lot of respect for him. He played incredible tennis this year already."

Fourth seed Holger Rune was forced to retire trailing 6-4 4-0 to home wild card Gijs Brouwer, sending the Dutchman through to a last-eight clash with countryman Tallon Griekspoor.

Daniil Medvedev eased to a 6-2 6-2 victory over Botic Van De Zandschulp while there were also wins for third seed Felix Auger-Aliassime and Australian Alex De Minaur.

At the Argentina Open in Buenos Aires, Dominic Thiem suffered another early loss, going down 6-4 6-4 to qualifier Juan Pablo Varillas.

Over at the WTA Tour's Qatar Open, Maria Sakkari edged out Caroline Garcia to reach the semi-finals.

Third seed Garcia had battled back from a set down to take the second on a tie-break, and there were no breaks of serve in either the second or third sets.

But it was Greek fifth seed Sakkari who eventually came out on top, clinching a deciding tie-break after two hours and 41 minutes to seal a 6-2 6-7 (5) 7-6 (5) victory.

In the last four Sakkari will take on second seed Jessica Pegula, who saw off Brazil's Beatriz Haddad Maia 6-3 6-2.

Top seed and defending champion Iga Swiatek was given free passage through to the semi-finals after Belinda Bencic withdrew and there she will take on eighth seed Veronika Kudermetova, who upset Coco Gauff 6-2 3-6 6-1.