Anastasia Pavlyuchenkova made an uncertain start to the defence of her Monterrey Open title after being pushed all the way in her first-round encounter with Eleni Daniilidou.
Pavlyuchenkova, the second seed at this hard-court event behind Serbia’s Jelena Jankovic, looked in good touch in the first set but lost the second on a tie-breaker as her Greek opponent found her range.
The Russian held it together in the decider, however, claiming two breaks of serve to Daniilidou’s one to prevail 6-2 6-7 (5/7) 6-4 in two hours and 51 minutes.
Julia Goerges of Germany became the second of the leading seeds to crash out as she went down to a straight-sets loss to Ksenia Pervak of Russia.
Goerges, the fourth seed, slumped to a 6-1 7-5 defeat to bow out just 24 hours after third seed Aravane Rezai also fell at the first hurdle.
Fifth-seeded Anastasija Sevastova of Latvia had no such problems as she defeated Laura Pous-Tio of Spain 6-2 6-4, while Sara Errani of Italy, the sixth seed, was a 6-2 6-4 winner over Johanna Larsson of Sweden.
Barbora Zahlavova Strycova defeated Romina Oprandi 6-0 4-6 6-1, Alize Cornet was a 7-5 6-1 victor against Simona Halep and Melanie Oudin beat fellow American Vania King 6-4 6-1
There were also first-round wins for Olga Govortsova, Sybille Bammer, Lucie Hradecka and Aleksandra Wozniak.
Top seed Jankovic meets Lourdes Dominguez Lino in the first round on Wednesday.