Petra Kvitova's return from maternity leave after a 17-month absence ended in defeat as Britain's Jodie Burrage battled back to win in three sets at the ATX Open.
Two-time Wimbledon champion Kvitova, 34, was contesting her first WTA match since 2 October 2023, at the China Open in Beijing.
The Czech made a positive start and won the opening set but the 25-year-old Burrage outlasted her opponent to win 3-6 6-4 6-4.
Burrage, ranked 189 in the world, will play Australian Ajla Tomljanovic in the second round.
Kvitova, who gave birth to her son, Petr, last July, did not know whether she would return to tennis before her break.