Alize Cornet survived a scare against Isabella Shinikova to book her place in the second round of the Katowice Open.
Cornet, the fourth seed and 2014 champion, comfortably won the first set against qualifier Shinikova, who levelled the match by coming out on top in a second-set tie-break.
The world number 45 recovered quickly and saw out a 6-2 6-7 (5-7) 6-3 win over the Bulgarian, ranked 189 places below her.
Third seed Jelena Ostapenko breezed past Daniela Hantuchova 6-1 6-1 in under an hour, while Camila Giorgi - runner-up in 2014 and 2015 - overcame Aliaksandra Sasnovich 6-4 6-4.
Dominika Cibulkova had to come from behind to beat Carina Witthoeft 6-7 (6-8) 6-4 7-6 (7-3) in a match that lasted over three hours.
World number 264 Ekaterina Alexandrova will be in the second round after defeating Klara Koukalova in straight sets 6-0 7-6 (7-5).
There were also wins for Viktorija Golubic, Francesca Schiavone, Magda Linette and Naomi Broady.