Emma Raducanu succumbed to defeat by teenager Maya Joint in an edgy second-round match at Eastbourne.
The 22-year-old lost 4-6 6-1 7-6 (7-4) to the Australian 19-year-old, who secured just the second grass-court win of her career.
Former US Open champion Raducanu rallied from 5-2 down in the deciding set to force a tie-break.
But the out-of-sorts Briton could not make it two comeback victories in as many days, having fought back from a set down in an emotional first-round win on the south coast.
Earlier, defending Wimbledon champion Barbora Krejcikova saved match points against a British player for the second day in a row to reach the quarter-finals.
Jodie Burrage held three match points on Krejcikova's serve in the deciding set but the Czech, playing only her sixth match this year after a lengthy lay-off with a back injury, battled to a 6-4 4-6 7-6 (7-3) win.
Raducanu arrived in Eastbourne as the British number one, having enjoyed a run to the quarter-finals at Queen's a fortnight ago.
But as she prepares for her fourth Wimbledon appearance - where she has twice reached the fourth round - her performance at Eastbourne looked laboured.
Former US Open champion Raducanu rallied from 5-2 down in the deciding set to force a tie-break.
But the out-of-sorts Briton could not make it two comeback victories in as many days, having fought back from a set down in an emotional first-round win on the south coast.
Earlier, defending Wimbledon champion Barbora Krejcikova saved match points against a British player for the second day in a row to reach the quarter-finals.
Jodie Burrage held three match points on Krejcikova's serve in the deciding set but the Czech, playing only her sixth match this year after a lengthy lay-off with a back injury, battled to a 6-4 4-6 7-6 (7-3) win.
Raducanu arrived in Eastbourne as the British number one, having enjoyed a run to the quarter-finals at Queen's a fortnight ago.
But as she prepares for her fourth Wimbledon appearance - where she has twice reached the fourth round - her performance at Eastbourne looked laboured.
