Ustero and Alonso beat Martina Fassio and Sandra Hernandez in the final round of qualifying 7-6 6-4, putting the teenage Spaniards into the round of 32 in Toulouse.
Ana Fernandez and Maria Rodriguez were two more Spaniards who made it through all of qualifying, dispatching Noa Canovas and Jimena Velasco with ease; 6-2 and 6-1.
Arantxa Soriano and Sandra Bellver too had few problems in their effort on Tuesday, beating Marta Borrero and Italian Carlotta Casali 6-2 6-3 in just over an hour time.
Two Italians that had more success were Emily Stellato and Giulia Sussarello. They beat Sara Pujals and Lara Arruabarrena after a comeback, 5-7 6-3 6-2.
Check out the full draw below!
