Johanna Konta went out in the first round of the Budapest Grand Prix.
The British No.3 rallied from a set down to take her match with Montenegro's Danka Kovinic, a player ranked 24 places below her in the world, to three sets.
But the 22-year-old ran out of steam in the decider, eventually succumbing to a 6-2 3-6 6-2 loss in one hour 53 minutes.
The top two seeds in the tournament, Lucie Safarova and Alize Cornet, also made early exits.
Safarova went down 6-1 6-0 to Valeria Solovyeva, while Cornet was beaten 6-4 6-2 by Andrea Hlavackova.
Sixth seed Chanelle Scheepers is safely through to the second round after seeing off Michaela Honcova 6-4 6-1 and eighth seed Anna Tatishvili was also a winner, ending the hopes of Reka-Luca Jani 6-3 6-4.
There were also wins on Tuesday for Petra Martic, Shahar Peer, Yvonne Meusburger, Alexandra Cadantu and Timea Babos.