13:08 CET - Over in Guangzhou, Veronika Erjavec is through after a battling 6-4, 6-7(7), 6-2 victory over Tatjana Maria, while home favourite Xiyu Wang has seen off Francesca Jones 6-4, 6-4.
11:33 CET - Eighth seed Karolina Muchova has progressed to the next round in Tokyo after her opponent Marketa Vondrousova was forced to retire with injury, while trailing 6-2, 1-0.
09:02 CET - Talented Aussie teenager Maya Joint is through in Tokyo after a 1-6, 7-6(5), 6-2 comeback triumph over Viktorija Golubic, while Anna Kalinskaya has beaten Suzan Lamens 6-3, 6-1.
07:53 CET - We've had a couple of early results in Tokyo, with McCartney Kessler recovering from a set down to beat Cristina Bucsa 3-6, 7-5, 6-3 and Eva Lys powering her way past Katie Boulter in straight sets, 6-2, 6-1.
Varvara Gracheva has also advanced in Japan after a hard-fought 4-6, 6-3, 6-4 win over Xinyu Wang.
Looking ahead to the rest of the day, the standout match comes at 10:00 CET, when Karolina Muchova takes on former Wimbledon champion and compatriot Marketa Vondrousova in Tokyo.
Elsewhere, Alex de Minaur and Karen Khachanov open their campaigns in Vienna, while there's also plenty of intriguing first-round action in Basel and Guangzhou.
07:30 CET - Good morning and welcome to our coverage of today's tennis!