Emma Raducanu has crashed out of the Qatar Open after a first round 0-6 6-7 (6) defeat to Anhelina Kalinina.
The British no7 squandered a set point in a second-set tie-break before losing in Doha.
Raducanu had been granted a wild card for the first WTA 1000 event of the season, but slipped to a fourth defeat in seven matches since returning from injury.
Ukrainian Kalinina sailed through a one-sided first set, which lasted little over half an hour.
Raducanu saved two match points at 6-5 down in the second set to force a tie-break and was one point away from squaring the match while leading that 6-5.
But world number 30 Kalinina held her nerve and will now face Latvia's eighth seed Jelena Ostapenko in the second round.
Kalinina won the opening game of the match on Raducanu's serve and broke the Brit twice more, while comfortably holding her own serve without facing any break points to take the opening set 6-0.
Raducanu came under immediate pressure at the start of the second set, losing her serve for the fourth consecutive time before responding to break back and win her first game of the match.
The following eight games all went with serve, with Raducanu saving five break points to lead 4-3.
After being broken for a fifth time in the match to trail 6-5, the Briton responded again, saving two match points against Kalinina's serve to force a tie-break.
Raducanu served for the set at 6-5 up in the tie-break, but lost the next two points on her serve and Kalinina sealed victory on her third match point.
