Paul-Henri Mathieu upset sixth-seeded Albert Ramos-Vinolas 7-5, 6-3 to reach the second round of the Grand Prix Hassan II on Tuesday.
The 34-year-old Mathieu won the clay-court tournament when it was held in Casablanca back in 2007.
Fifth-seeded Teymuraz Gabashvili also bowed out, losing 6-3, 6-4 to last year's runner-up Daniel Gimeno-Traver.
Eighth-seeded Jiri Vesely also progressed by defeating Inigo Cervantes 6-1, 6-3. He was joined in the second round by Nicolas Almagro, who beat Radu Albot 6-4, 6-3 to set-up an all-Spanish match against top-seeded Guillermo Garcia-Lopez.