14:09 CET - Third seed Flavio Cobolli is through to the quarter-finals in Almaty, with the Italian proving too strong for Rinky Hijikata in straight sets, 6-4, 7-5.
12:52 CET - Over to Ningbo, where Ana Tomljanovic has prevailed against Turkey's Zeynep Sonmez to make it into the next round, winning their encounter in straight sets 7-6(6), 6-3 in one hour and 51 minutes.
12:32 CET - Nikoloz Basilashvili is today's first winner in Brussels after a relatively routine 6-4, 6-4 win against Quentin Halys.
Over in Almaty, sixth seed Alex Michelsen and James Duckworth have progressed after victories over Beibit Zhukayev and Gabriel Diallo, respectively.
10:45 CET - Sixth seed Belinda Bencic has survived a scare in Ningbo, coming from a set down to outlast Yuliia Starodubtseva in a three-and-a-half-hour epic, 5-7, 6-4, 7-5.
10:41 CET - Sorana Cirstea has eased through in Osaka after a convincing 6-3, 6-1 victory over Katie Boulter in just 70 minutes.
09:35 CET - Top seed Naomi Osaka is through to the next round at the Japan Open, with the home favourite surviving a second-set wobble to battle past Suzan Lamens 7-6(6), 3-6, 6-2.
Meanwhile, in Almaty, Jan-Lennard Struff and Shintaro Mochizuki have both progressed.
08:38 CET - Looking ahead to the rest of the day, there are plenty of star names in action, including Mirra Andreeva, Casper Ruud and Karolina Muchova.
Check out the full schedule for tournaments in Ningbo, Osaka, Stockholm, Brussels and Almaty via the links.
Meanwhile, the Six Kings Slam in Saudi Arabia gets underway later this evening, with Alexander Zverev facing Taylor Fritz at 18:30 CET before Jannik Sinner comes up against Stefanos Tsitsipas.
08:09 CET - There have already been a couple of early results in Osaka, with Olga Danilovic seeing off Ashlyn Krueger in straight sets, 6-4, 6-4, and Jaqueline Cristian coming from a set down to beat Jessica Bouzas Maneiro 0-6, 6-4, 6-2.
Staying in Osaka, home favourite and top seed Naomi Osaka is currently on court against Suzan Lamens, while over in Ningbo, Belinda Bencic is facing Yuliia Starodubtseva.
07:40 CET - Good morning and welcome to our coverage of today's tennis!