Katie Boulter fell to a 6-1 6-4 defeat to Katerina Siniakova in the semi-finals of the Japan Open.
Boulter had reclaimed the British No 1 ranking from Sonay Kartal after reaching her third semi-final of the season in Osaka.
But the 30-year-old’s run was halted by the Czech Siniakova, the world doubles No 1 who is hunting her first singles title in three years.
Siniakova, ranked No 86 in singles, flew out of the blocks and won the first five games of the match, with Boulter needing to save set point to avoid a bagel set.
Boulter, who produced a comeback victory against Antonia Ruzic in the quarter-finals, broke early in the second set but Siniakova did not allow her to build momentum.
Siniakova showed frustration as Boulter put up a fight, with the Briton saving six break points in the ninth game of the set, before the Czech eventually converted.
She then served out the win at the first opportunity and the 12-time grand slam doubles champion will play Ashlyn Krueger on Sunday in the 11th singles final of her career.
Boulter will re-enter the world’s top-50 as a result of her wins in Osaka, rising two places ahead of Kartal after her brilliant run to the Wuhan Open final last week.