Tennis Tracker: Sinner beats Struff in thriller, Zverev and Paul seal wins
21:44 CET - In the final two matches of the day, Sebastian Korda (23) fought from a set down at Queen's to beat Rinky Hijikata (23) 6-7(4), 6-3, 6-4, while Zhizhen Zhang (27) battled past Christopher Eubanks (28) 6-4, 4-6, 7-5 to move into the semis in Halle.
20:42 CET - Ajla Tomljanovic's (31) good performances on the grass show no sign of letting up, defeating Leylah Fernandez (21) 1-6, 6-3, 6-2 to move into the semi-finals in Birmingham.
19:34 CET - World No.1 Jannik Sinner has survived a huge scare against Jan-Lennard Struff (34), beating the German 6-2, 6-7(1), 7-6(3) in Halle.
Over at Queen's, Jack Draper (22) was unable to follow up his victory over Carlos Alcaraz (21), falling to Tommy Paul (27) 3-6, 7-5 4-6.
16:42 CET - Alexander Zverev (27) is through to the last four in Halle after recovering from a set down to outlast France's Arthur Fils (20) 6-7(5), 6-3, 6-4.
Lorenzo Musetti (22) was also victorious at Queen's, beating Brit Billy Harris (29) 6-3, 7-5.
16:28 CET - Another result to bring you from Birmingham, with Anastasia Potapova (23) defeating second seed Barbora Krejcikova (28) 6-1, 6-4 in just over an hour.
15:38 CET - Meanwhile, in Birmingham, Elisabetta Cocciaretto (23) is the first woman through to the semi-finals after a 5-7, 6-4, 6-2 victory over Diana Shnaider (20).
14:43 CET - The highest remaining seed Taylor Fritz (26) has been dumped out of Queen's, falling 4-6,3-6 to Jordan Thompson (30).
13:51 CET - Our first result from Halle, where Hubert Hurkacz (27) has swanned into the next round with a 7-6(5), 6-4 win over Marcos Giron (30) to advance into the semi-final.
11:47 CET - Unfortunately there has been some bad news in Berlin. No.3 seed Elena Rybakina (25) - who appeared to be really unwell on court - has retired from her match against Victoria Azarenka (34) just four games into the match. Hopefully it is nothing too serious for the Kazakh ahead of Wimbledon, while Azarenka swiftly moves into the semi-finals.
09:30 CET - We've got a brilliant day of tennis ahead, with Jannik Sinner (22) and Alexander Zverev (27) both in action in Halle, while Elena Rybakina (25), Coco Gauff (20) and Aryna Sabalenka (26) all take to the court in Berlin.
Check out the schedules for all four of this week's tournaments below:
Berlin (WTA) & Birmingham (WTA)
09:10 CET - Good morning and welcome to our coverage of today's tennis action!