Great Britain's Francesca Jones was unable to replicate her eye-catching Copa Colsanitas run from last year as she fell in three sets to Laura Siegemund in the second round.
The injury-plagued 23-year-old - who reached the semi-finals of the 2023 edition - made light work of home favourite Yuliana Monroy in the first round for her maiden WTA Tour triumph of the year, and she was on track for a surprise win over seventh seed Siegemund.
However, the German - who sits 125 places higher than Jones in the WTA standings - came from behind to triumph 6-7[4] 6-4 6-2 as Jones ran out of steam towards the end of their two-hour and 57-minute showdown.
Three times Jones went a break up in a tense first set, and three times Siegemund fought back immediately - including when the Briton was serving for the opener - but Jones valiantly battled back from 3-1 down in the tie-breaker to establish a slender advantage.
The world number 214's inability to back up breaks proved costly in the second, though, as a plucky Siegemund recovered from 3-1 and 4-2 down to force a decider, where she would be the one to draw first blood with a quick break.
On that occasion, it was Jones's turn to immediately draw level in a back-and-forth contest, but her German foe held her nerve when it mattered most, reeling off a four-game winning sequence to reach the quarter-finals, where she will meet top seed Marie Bouzkova.
Jones was one of three Britons to bow out of top-level tournaments on Thursday, as Dan Evans and Jan Choinski both suffered second-round eliminations in Casablanca and Estoril respectively. body check tags ::
