21:37 CET - Kei Nishikori (33) has beaten Jordan Thompson (28) in Newport 7-6, 7-6.
20:43 CET - Here is our ATP Flashmoment of the day.
19:27 CET - Into the second round in Warsaw goes home favourite Iga Swiatek (22) after a 6-4, 6-3 victory over Nigina Abduraimova (29).
Elsewhere, Heather Watson (31) upset third seed Katerina Siniakova (27).
18:08 CET - Meanwhile, on the women's side, Donna Vekic (27) suffered a shock 3-6, 6-3, 6-3 defeat to world No.154 Storm Hunter. Bernarda Pera (28) didn't have as many problems though, downing Kaia Kanepi (38) 7-6(6), 6-1.
18:03 CET - A few more updates from Hamburg. Arthur Fils (19) was made to work by Daniel Elahi Galan (27) but eventually came out on top 7-5, 7-5, while Alejandro Davidovich Fokina (24) outlasted Pedro Cachin (28) 2-6, 7-5, 6-2.
17:00 CET - French Open finalist Karolina Muchova (26) has won in three sets against Aliaksandra Sasnovich (29) 4-6, 7-6, 6-3 in Warsaw, meanwhile in Lausanne the tournament's second seed Elisabetta Cocciaretto (22) is also through in three sets, battling back in a 3-6, 7-6, 6-2 contest against Celine Naef (18).
15:47 CET - Alexander Zverev (26) is through to the next round of his home tournament in Hamburg, dismantling Alex Molcan (25) 6-0, 6-3.
14:34 CET - Back in Hamburg, third seed Lorenzo Musetti (21) has defeated Elias Ymer (27) 6-4, 6-1 to progress into the next round, whilst Camila Osorio (21) has taken down Martina Trevisan (29), also in straight sets, this time 6-1, 6-3.
14:09 CET - Mixed news for seeds around Europe with Mayar Sherif (27) - the second seed in Hamburg - has been comprehensively knocked out by German Eva Lys (21) 6-1, 6-1. Over in Lausanne, fifth seed American Emma Navarro (22) had very little trouble getting past Leolia Jeanjean (27) 6-0, 6-0.
Whilst in Warsaw, Tereza Martincova (28) has knocked out the fifth seed Shuai Zhang (34), beating her in straight sets 7-6, 6-4.
11:50 CET - A lot of tennis happening around the world today, and we have our first result from Warsaw where, in an all Chinese affair, fourth seed Lin Zhu (29) has seen off compatriot Xiyu Wang (22) in straight sets 6-4, 6-2.
07:30 CET - Welcome back to the Tennis Tracker this Tuesday morning. We have some big names in action today; namely Iga Swiatek (22), Karolina Muchova (26) and Alexander Zverev (26). As usual, we will have highlights and results for you from all the tournaments on the ATP and WTA Tours, so stay tuned throughout the day.