Top seed Albert Ramos-Vinolas was knocked out of the Grand Prix Hassan II in Morocco, falling in straight sets 7-6, 6-2 to qualifier Alexey Vatutin.
The Russian broke the Spaniard five times on his way to victory and will take on Pablo Andujar in the quarterfinals.
Elsewhere, Richard Gasquet overcame Guillermo García-Lopez 6-2, 6-4 to set up a quarterfinal with fellow Frenchman Gilles Simon, who battled past Roberto Carballes Baena.
Simon was pushed hard in the opening set but eased through the second for a 7-5, 6-1 victory.
In a day of shock defeats, Morocco native and world No. 617 Lamine Ouahab fought from a set down to beat world No. 34 Philipp Kohlschreiber 2-6, 6-0, 7-6. Nikoloz Basilashvili now awaits in the second round.
Kyle Edmund found out his last-16 opponent after Romanian Radu Albot overcame Italian Andreas Seppi 1-6, 6-3, 6-0. If the British No. 1 finds his way past Albot, a meeting with either Mischa Zverev or wild-card Malek Jaziri awaits after the latter fought from a set down to beat Marton Fucscovics 1-6, 6-4, 6-2.