Tennis Tracker: Muchova and Rublev on wrong end of upsets, Ruud through in Hamburg
23:45 CET - In the first match of the day from Atlanta, third-seeded Brit Daniel Evans (33) was bundled out in the second round by Gemrany's Dominik Koepfer (29) 2-6, 7-6(3), 6-4.
Tune in to the Tennis Tracker tomorrow for results from the rest of Thursday's play in Atlanta.
21:50 CET - Jodie Burrage (24) may have been defeated 6-4, 6-1 by Lucrezia Stefanini (25) in Warsaw today but she won the pick of the ladies' points from Thursday's play.
21:45 CET - Earlier, Lorenzo Musetti (21) overcame Jozef Kovalik (30) from a set down, 3-6, 6-2, 6-4, in their clash in Hamburg.
Musetti winning what seemed like a never-ending rally was our pick of the day's play from the men's side. Kovalik just couldn't keep him down!
19:24 CET - There's been a big upset in Hamburg, with second seed Andrey Rublev (25) losing 6-2, 6-2 to Daniel Altmaier (24).
19:19 CET - World number Iga Swiatek (22) has claimed victory on home turf, winning 6-2, 6-2 against Claire Liu (23).
18:30 CET - Dominic Thiem's (29) struggles continue, with the former world number three losing 6-3, 7-5 to top seed Jiri Lehecka (21) in Croatia.
17:50 CET - Casper Ruud (24) is through in Hamburg having come from behind to beat Cristian Garin (27) 1-6, 6-2, 6-2.
15:51 CET - Karolina Muchova (26) has been dumped out of Warsaw, losing to world No.174 Rebecca Sramkova (26) 7-5, 3-6, 7-5 in just under three hours.
15:47 CET - Over on the men's side in Hamburg, Arthur Fils (19) defeated Dusan Lajovic (33) 7-5, 7-5, while Lorenzo Musetti (21) overcame Jozef Kovalik (30) from a set down, 3-6, 6-2, 6-4.
15:00 CET - More results from Warsaw where Czech rising star Linda Noskova (18) has progressed to the quarterfinals after beating Slovakia's Viktoria Hruncakova (25) 6-3, 6-3.
13:33 CET - Let's round up some early results for you. In Warsaw, Heather Watson (31) battled past Yuliya Hatouka (23) 6-2, 5-7, 6-1, while fellow Brit Jodie Burrage (24) was defeated 6-4, 6-1 by Lucrezia Stefanini (25).
In Hamburg, Jule Niemeier (23) was shocked by Daria Saville (29) 6-3, 6-2, and over in Lausanne, Sara Sorribes Tormo (26) fell at the hands of Tamara Zidansek (25) 6-3, 7-5.
08:00 CET - Hello and welcome to our coverage of today's tennis. With a number of top players taking to court, we'll be bringing you updates on all the action in Hamburg, Warsaw, Atlanta, Lausanne and Umag.