Katie Boulter's winning run ended with defeat by China's Zhu Lin in the first round of the Rothesay Classic in Birmingham.
Boulter celebrated the best achievement of her career in Nottingham on Sunday when she won her first WTA Tour title to reach a new highest ranking of 77.
It cemented her position as British number one in the absence of the injured Emma Raducanu, but Boulter was unable to back it up at Egbaston Priory, where she made the quarter-finals last year.
Boulter certainly had her chances against Zhu, ranked 39, but she was unable to convert enough of them in a 7-5 7-5 defeat.
Boulter began well, opening up a 3-1 lead, but Zhu responded strongly and took her second set point in the 12th game.
The second set was a rollercoaster featuring seven breaks of serve and 17 break points.
Boulter was only able to take three of her 10 opportunities, though, and - after saving two match points at 4-5 - she sent a backhand long on the third, two games later.
Play did not get under way until 1.30pm because of rain, with second seed Jelena Ostapenko battling to a three-set win over Czech teenager Linda Noskova in the opening match.
