Emma Raducanu is out of the Ostrava Open after losing to fifth seed Daria Kasatkina in the first round.
The defeat comes after British number one Raducanu retired injured from her Korea Open semi-final against Jelena Ostapenko on 24 September.
Raducanu has struggled with injuries during her first full year on the WTA tour as she seeks to build on her 2021 US Open victory.
Kasatkina will play fellow Russian Ekaterina Alexandrova in the next round.
But there was British success elsewhere for Dan Evans and Harriet Dart.
Evans beat Moldova's Radu Albot 6-7 (3-7) 6-1 6-4 at the Rakuten Open in Tokyo while Dart beat Spain's Nuria Parrizas-Dias 6-2 6-4 at the Jasmin Open in Tunisia.