13:55 CET - There's been another upset in Almaty with top seed Frances Tiafoe (26) losing 6-2, 7-6 to Aleksandar Vukic (28), who saved two set points in a thrilling final tiebreak.
In Stockholm, fourth seed Tommy Paul (27) has beaten Miomir Kecmanovic (25) 7-6, 6-2 to progress to the semi-finals.
12:47 CET - Mirra Andreeva (17) is through to the semi-finals in Ningbo with fourth seed Barbora Krejcikova (28) retiring with an injury while trailing 7-6, 3-2.
12:03 CET - Francisco Cerundolo (26) has eased past home favourite Alexander Shevchenko (23) in Almaty, winning 6-2, 6-3 in just over an hour.
Over in Osaka, Diane Parry (22) secured a hard-fought 6-3, 1-6, 6-3 win against Clara Tauson (21).
10:50 CET - The first quarter-final has been won by Daria Kasatkina (27) with the fifth seed beating Yulia Putintseva (29) 6-4, 1-6, 7-6, saving two match points in the process.
In Almaty meanwhile, second seed Alejandro Tabilo (27) has lost 3-6, 6-3, 6-4 to Gabriel Diallo (23) of Canada.
10:07 CET - Two of the quarter-finals have already been completed in Osaka with Suzan Lamens (25) and Aoi Ito (20) both securing a spot in the final four.
You can follow the two remaining matches of the day here.
10:00 CET - Hello and welcome to Flashscore's coverage of today's tennis!
Some big news broke overnight, with world number nine Danielle Collins (30) announcing that she's calling off her plans to retire and will play on in 2025.
