Qualifier Albert Ramos-Vinolas will face world number one Novak Djokovic in round two of the Monte Carlo Masters after defeating Robin Haase.
Spain's world number 67 Ramos-Vinolas stormed past Dutchman Haase 6-1 6-1 in the clay-court tournament.
Elsewhere in the draw, Andreas Haider-Maurer has booked a second-round meeting with Bernard Tomic after making short work of world number 17 Ernests Gulbis - winning 6-1 6-0.
Germany's Philipp Kohlschreiber was another to win in straight sets on Monday, as did both Roberto Bautista Agut and John Isner.
Source: PA